Pneumatic Boot Therapies

Abstracts

• Abu-Own A, Cheatle T, Scurr JH, and Smith PDC: Effects of intermittent pneumatic compression of the foot on the microcirculatory function in arterial disease. Eur J Vasc Surg 7: 488-492, 1993. Abstract: The venous pump of the foot assists blood returning to the heart. The aim of this study was to evaluate the effect of mechanical activation of the foot pump on the microcirculation of the skin in patients with peripheral occlusive arterial disease. Design: single parallel group comparing patients with arterial disease to normal control subjects. Setting: Department of Surgery, the University College and Middlesex Hospital, London, U.K. Subjects and materials: 15 patients with occlusive arterial disease and 15 control subjects. A pneumatic impulse foot pump was applied to the foot. Outcome measures: the Laser Doppler flux (LDF) and transcutaneous oxygen tension (tcPO2 ) were measured on the big toe with the subject supine, before, during and after a 10 min period of foot pumping. The study was repeated with the subject sitting. Results: on sitting there is a fall in LDF and a rise in tcPO2. Application of intermittent pneumatic compression of the foot in the sitting position resulted in an increase in LDF. In patients, the median percentage increase was 57% and the median difference was 82 arbitrary units (AU)(95%CI 60-130, p< 0.001). In controls, the median percentage increase was 66% and the median difference was 124 AU (95%CI 73-275 p < 0.001). There was a corresponding "further" increase in tcPO2 in both groups of subjects. In patients, the median percentage increase was 8%, in controls the median percentage increase was 10% p < 0.01). Conclusion: we conclude that intermittent pneumatic compression of the foot in the dependent position increases. LDF and tcPO2 Comments: The authors used a mini-pump limited to the foot. They did not pump on the diseased areas of the calf and thigh and they pumped but a brief time (10 minutes) and the effect on LDF was brief fading "away within 20s of stopping the foot pump". Here they are reporting on LDF and tcPO2. Allwood (Clin Sc 16:231, 1957) pumped on the lower calf and documented an increase in blood flow in the foot with a plethysmographic method. Loan ( J Appl Physiol 14(3): 411-413, 1959) rhythmically inflated a cuff around the ankle in the seated position and noted an increase in blood flow in the foot by three methods: venous occlusion plethysmography, heat flow and calorimetry. Henry and Winsor (Am Heart J 70:79-88, 1965) pumped from the head of the fibula to the malleoli and documented increased flow in the foot by measuring falloff in counts from injected I131. Gaskell and Parrott (Surg Gyn & Obstet 146:583-592, 1978) pumped on the foot and ankle and documented an increased clearance of 133 Xe from the dorsum of the foot. See Eze, Comerota et al below for more recent work with non-cardiosynchronous calf and foot pumps.
  
  
• Agerskov K, Tofft HP, Jensen FB, Engell HC: External negative thigh pressure. Effect upon blood flow and pressure in the foot in patients with occlusive arterial disease. Dan Med Bull 37:451-4, 1990. We studied the effect of external application of 35-45 mmHg negative pressure around the thigh on toe blood pressure and skin blood flow in nine patients with occlusion of the superficial femoral artery and rest pain/severe intermittent claudication. The systolic toe blood pressure increased from 32 (range 5-70) mmHg before treatment to 57 (42-75) mmHg (p less than 0.05) during negative thigh pressure and 44 (range 10-88) mmHg after treatment. In addition, the gain in toe blood pressure tended to be greater the lower the pre-test toe pressure was, correlation coefficient r = 0.52 (p greater than 0.05). Relative skin blood flow, measured in the first toe interstice by the 133Xe wash-out method, increased by 304 (range 86-767) percent (p less than 0.05) during the test period compared to the mean wash-out rate obtained before and following the test period. Heart rate, systemic blood pressure, skin temperature, serum protein and haematocrit measured during each phase of the study were similar. We conclude that 35-45 mmHg negative pressure around the thigh in patients with occlusion of the superficial femoral artery induce increased blood perfusion in the foot, possibly due to changes in collateral arterial resistance in the thigh. Comments: The suction-pressure boots in use in the 1930's utilized alternating negative pressure and positive pressure in the supine position. An air seal, of course, is necessary in the upper thigh in such boots and the alternation in negative and positive pressure resulted in considerable shear forces at the air seal; the treatment was stressful to both the skin and underlying tissue. Thirty mm Hg is equivalent to about 17 inches of water pressure, about the distance from the aortic valve to the midthigh in the sitting position. Merely by sitting up during therapy with the Circulator Long-Boot, one gains the benefits of gravity and an equivalent of about 30 mm Hg negative pressure. The treatment is well tolerated and no skin breakdown occurs.
  
  
• Alpagut U, Dayioglu E: Importance and advantages of intermittent external pneumatic compression therapy in venous stasis ulceration. Angiology. 56:19-23, 2005. Venous ulcers are seen following postthrombophlebitic syndrome with venous insufficiency and can begin as a result of minor trauma. In this retrospective study the authors examined the value of external intermittent pneumatic compression therapy in chronic venous ulcers. Results in 1,250 patients with postthrombophlebitic syndromes, 235 of these patients with leg ulcers, revealed that this modality of therapy shortens the therapy duration, lowers the total therapy cost, and hastens the return to active life in comparison to the classical therapy with compression stockings and antiaggregant or low-dose oral anticoagulant therapy. In the light of their findings they propose the wider use of this adjuvant therapy.
  
  
• Amsterdam EA, Lee G, Tonkon MJ, DeMaria AN and Mason DT: Noninvasive circulatory assistance by external counterpulsation. Chapter 14 in Advances In Heart Disease, Volume I, Mason DT editor. Grune & Stratton New York, 1977. The duration of applied pressure was approximately 250 msec. In normal subjects diastolic blood pressure was elevated 40-70% and cardiac output increased 15-60% during the treatment. Treatment of angina patients for one hour daily for 5 days resulted in symptomatic improvement in 17 of 21 individuals with definitely improved angiograms in 5 of 11 and equivocally improved angiograms in 4 of the 11 patients undergoing coronary angiography. An increased vascularity was seen in the angiograms.
  
  
• Applebaum RM, Kasliwal R, Tunick PA, Konecky N, Katz ES, Trehan N and Kronzon I: Sequential external counterpulsation increases cerebral and renal blood flow. Am Heart J 133: 611-615, 1997. Abstract: The purpose of this study was to evaluate the effect of sequential external counterpulsation (SECP) on cerebral and renal blood flow. The effect of SECP on carotid and renal artery blood flow was studied in 35 and 18 patients, respectively. With a portable unit, cuffs were applied to the calves and thighs, sequentially inflated with air at the onset of diastole and deflated at the onset of systole. Carotid and renal Duplex studies were performed during intermittent SECP. Diastolic augmentation of carotid and renal artery flow velocity was observed in all patients. The mean carotid flow integral increased by 22% from 27.7 ± 1.8 cm to 33.1 ± 2.3cm (P=0.001). The mean renal artery flow velocity integral increased by 19% from 21 ± 1 cm to 25 ± 1 cm (P=0.0001). With SECP, a new diastolic Doppler flow velocity wave was observed was observed, with an average peak carotid diastolic flow velocity of 56 ± 4 cm/sec and an average peak renal artery diastolic flow velocity of 40 ± 2.5 cm/sec. This diastolic wave was 75% (carotid) and 68% (renal) as high as the systolic wave during SECP. In addition, with SECP the systolic wave increased 6% and 8% in the carotid and renal artery, respectively (P=0.02 and 0.006 respectively). In conclusion, SECP significantly increases carotid and renal blood flow. This noninvasive, harmless treatment may be useful to support patients with decreased cerebral and renal perfusion. Comment: Case 32 on this website demonstrates what these techniques may accomplish in diabetics with chronic renal failure. But is the treatment described in this article harmless? The ECP devices are generally contraindicated in the presence of leg ischemia. Consideration of the standard reactive hyperemia test in the vascular laboratory is helpful in understanding why. A cuff is placed around the upper thigh for a few minutes and released and the time required for the pulse wave to return to the ankle noted. No blood was delivered to the muscles of the thigh and calf during the placement of the cuff and anoxia of these tissues develops. When the cuff is removed in patients with arteriosclerotic lesions, the metabolic needs of the proximal tissues are met before the blood flow reaches more distal tissues. In a normal leg with an open conduit between the thigh and distal pulse, the distal pulse is quickly detected and the metabolic needs of the leg may be met more simultaneously. In the abnormal leg, however, it may take minutes before the distal pulse is detected. The pulse in the normal leg may be likened to a line of balls on a pool table; hitting one end with the Q-ball will knock a single ball off the end of the line of balls. In the normal leg, there is a column of blood from the heart to the groin and from there to the foot. The pulse wave is transmitted through this column of blood. If the leg is compressed with a bag containing pressure higher than the systolic pressure in the leg, the arterial blood is pressed backward towards the heart and the column of blood from the groin to the foot is gone. Restoration of the pulse at the ankle then requires not only meeting the metabolic needs of the proximal tissue but restoration of the column of blood from the groin to the ankle. Especially, in patients with peripheral arteriosclerotic lesions, the column of blood from the groin to the ankle is not continuous and fills slowly. It is apparent that the application of pressure to the leg that is greater than the systolic pressure at some level in the leg may produce distal ischemia. Even if the application of pressure is brief as in the ECP device, ischemia can and is produced in patients with peripheral vascular disease. If the application of pressure is longer, the pressure then blocks inflow of blood while it is applied. Thus, in the situation where a cuff is applied for a few seconds round the calf at a pressure higher than systolic pressure, a few beats are blocked from entering the calf while venous blood may be expressed from the tissue. Release of such a cuff, of course, will be associated with a brief surge of blood down the popliteal artery until it meets the first arterial lesion where it then is not further assisted. In contrast to these situations, the Circulator Boot compresses the leg with diastolic pressure and is so applied that a normally pressurized portion of the leg is included. Inflation of the Circulator Boot does not push blood out of the normally pressurized segment. Each pulse wave is allowed to enter the leg as best it can. The Circulator Boot then provides a compression both expelling the venous blood and providing a driving force to disseminate the arterial blood around the leg (much as one disseminates water around a sponge that it half wet when one squeezes it). If the heart rate is rapid and there is a question as to whether the time for blood inflow is too short, the Circulator Boot heart monitor signals to the operator to switch to 2:1 or 3:1 settings thus allowing one or two extra pulse waves to enter the leg before leg compressions. These timing considerations remain unique to the Circulator Boot systems and allow our successful treatment of ischemic legs. The rapid action of the Circulator Boot systems allows for the elaboration of endothelial factors as mentioned in our library on vascular hormone and clotting factors. Again, as noted below, we show the importance of these considerations in our commentary on the article by Eze AR et al.
  
  
• Akhtar M, Wu G-F, Du Z-M, Zheng Z-S, Michaels ADAm J Cardiol 98:28-30, 2006. Enhanced external counterpulsation (EECP) significantly augments diastolic blood flow and has been postulated to improve endothelial function by increased shear stress. We examined the effects of EECP on plasma nitric oxide and endothelin-1 (ET-1) levels. Plasma nitrate and nitrite (NOx) and ET-1 levels were measured serially in 13 patients with coronary artery disease who received 1-hour daily treatments of EECP over 6 weeks. During the course of EECP therapy, plasma NOx progressively increased and plasma ET-1 progressively decreased. After 36 hours of EECP, there was a 62 ± 17% increase in plasma NOx compared with baseline (43.6 ± 4.3 vs 27.1 ± 2.6 µmol/L, p <0.0001) and a 36 ± 8% decrease in plasma ET-1 (76.7 ± 9.5 vs 119.5 ± 8.5 pg/L, p <0.0001). At 3 months after completion of EECP, NOx remained 12 ± 11% above baseline (p = 0.002), and ET-1 remained 11 ± 10% below baseline (p = 0.0068). Our data provides neurohormonal evidence to support the hypothesis that EECP improves endothelial function.
  
  
• Bergan JJ, Sparks S, Angle N: A Comparison of Compression Pumps in the Treatment of Lymphedema. Vascular and Endovascular Surgery 32:455-462, 1998. Purpose: This study was done in order to ascertain which methods of mechanical compression would be optimum in treating patients with primary and secondary lymphedema. Materials and Methods: Thirty-five patients (26 women, 9 men) were enrolled in the study. The women ranged in age from 36 to 82 years (mean 56.9 years). The men ranged in age from 31 to 83 years (mean 56.4 years). Ultimately, 32 patients completed the study. Each patient was treated by random assignment to each of the three types of compression pumps. The treatment arms were as follows: (1) unicompartmental nongradient pump with pressure of 50 mm Hg, (2) a three-compartment pump with segmental, nongradient pressures of 50 mm Hg in each of three cells, and (3) a multicompartmental gradient pressure pump with ten cells ranging in pressure from 80 at the most distal to 30 at the most proximal. There were 35 extremities treated by each of the three methods. Eleven had primary lymphedema and 24 had secondary lymphedema. Results: The mean percentage volume change was +0.4% in the limbs treated with the unicompartmental pump, +7.3% in the three-compartment pump, and -32.6% in the ten-compartment pump. By use of Kruskal and Wallis, one-way ANOVA on ranks, a significant difference between the three treatments was detected (p < 0.001). In treatment of primary lymphedema there was no difference between the subgroups with regard to the effect of the three compression pumps. In treatment of secondary lymphedema, there was no reduction in the size of the limbs treated with the single-compartment, there was a -4.65% reduction in the three-compartment pump treatment, and -28.4% in the tencompartment pump. There were no differences in treatment of secondary limbs with and without radiation. In an analysis comparing primary to secondary lymphedema with and without radiation, the results were not statistically different from one another. Other factors such as severity of lymphedema, gender, duration of lymphedema, history of infection, and presence of radiation could not be implicated as having prognostic significance or having any effect on response to therapy. Conclusions: Mechanical external pneumatic compression can produce a reduction in treated limb volumes in primary and secondary lymphedema. This is best achieved by multicompartment sequential compression. Limb volume reduction by single or three compartment devices is decidedly less effective in treatment of lymphedema.
  
  
• Blackshear WM, Pescott C, LePain F, Benoit S, Dickstein R, Seifert KB: Influence of sequential pneumatic compression of postoperative venous function. J Vasc Surg 5:432-6, 1987. Venous capacitance decreased from an ambulatory preoperative state (3.19(0.43cc/100 cc tissue) to the postoperative state of complete bedrest (2.08(0.34). Likewise, venous outflow decreased from 87.2(10.6 to 58.1(8.7 cc/100cc of tissue/min. When legs were pumped postoperatively with a sequential pneumatic device, the falloff was significantly less. The authors hypothesized that the improvement in venous function was induced by the direct mechanical effects of pumping on the vessel wall, humoral or neurogenic factors, or a Venturi effect through increased flow velocity in the vena cava.
  
  
• Bolli R, Marbán E: Molecular and cellular mechanisms of myocardial stunning. Physiol Rev 79:609-34, 1999. The past two decades have witnessed an explosive growth of knowledge regarding postischemic myocardial dysfunction or myocardial "stunning." The purpose of this review is to summarize current information regarding the pathophysiology and pathogenesis of this phenomenon. Myocardial stunning should not be regarded as a single entity but rather as a "syndrome" that has been observed in a wide variety of experimental settings, which include the following: 1) stunning after a single, completely reversible episode of regional ischemia in vivo; 2) stunning after multiple, completely reversible episodes of regional ischemia in vivo; 3) stunning after a partly reversible episode of regional ischemia in vivo (subendocardial infarction); 4) stunning after global ischemia in vitro; 5) stunning after global ischemia in vivo; and 6) stunning after exercise-induced ischemia (high-flow ischemia). Whether these settings share a common mechanism is unknown. Although the pathogenesis of myocardial stunning has not been definitively established, the two major hypotheses are that it is caused by the generation of oxygen-derived free radicals (oxyradical hypothesis) and by a transient calcium overload (calcium hypothesis) on reperfusion. The final lesion responsible for the contractile depression appears to be a decreased responsiveness of contractile filaments to calcium. Recent evidence suggests that calcium overload may activate calpains, resulting in selective proteolysis of myofibrils; the time required for resynthesis of damaged proteins would explain in part the delayed recovery of function in stunned myocardium. The oxyradical and calcium hypotheses are not mutually exclusive and are likely to represent different facets of the same pathophysiological cascade. For example, increased free radical formation could cause cellular calcium overload, which would damage the contractile apparatus of the myocytes. Free radical generation could also directly alter contractile filaments in a manner that renders them less responsive to calcium (e.g., oxidation of critical thiol groups). However, it remains unknown whether oxyradicals play a role in all forms of stunning and whether the calcium hypothesis is applicable to stunning in vivo. Nevertheless, it is clear that the lesion responsible for myocardial stunning occurs, at least in part, after reperfusion so that this contractile dysfunction can be viewed, in part, as a form of "reperfusion injury." An important implication of the phenomenon of myocardial stunning is that so-called chronic hibernation may in fact be the result of repetitive episodes of stunning, which have a cumulative effect and cause protracted postischemic dysfunction. A better understanding of myocardial stunning will expand our knowledge of the pathophysiology of myocardial ischemia and provide a rationale for developing new therapeutic strategies designed to prevent postischemic dysfunction in patients.Comments: Postoperative heart surgery disasters are usually treated with the aortic balloon which has a signifiant morbidity (http://www.circulatorboot.com/Newsletter/vol2numb3.html). In our Case 182, the balloon was associated with the development of significant leg ischemia and had to be discontinued. The use of the Circulator Boot not only restored blood flow to both legs but also benefited his heart (http://www.circulatorboot.com/casehistory/case182.html).
  
  
• Bondesson S, Pettersson Tet al: Effects on blood pressure in patients with refractory angina pectoris after enhanced external counterpulsation. Blood Press April, 2010, Abstract: Objective. Enhanced external counterpulsation (EECP) is a non-invasive technique that has been shown to reduce the frequency and severity of angina pectoris. Little is known how EECP affects the blood pressure. Methods. 153 patients with refractory angina were treated with either EECP or retained on their pharmacological treatment (reference group). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP) and heart rate were measured pre- and post-treatment and at 12 months follow-up. Results. EECP treatment altered the blood pressure in patients with refractory angina pectoris. A decrease in the blood pressure was more common in the EECP group compared with the reference group. In the reference group, an increase in the blood pressure was more common. A correlation between a decrease in blood pressure after EECP treatment and a higher baseline MAP, SBP and DBP was seen. No such correlation was seen in the reference group. The blood pressure response did not persist at 12 months follow-up. Conclusion. EECP treatment affects the blood pressure in patients with refractory angina pectoris. The decreased blood pressure may be a result of an improved exercise capacity, an improved endothelial function and vasoreactivity in general.Comments: Hypertension as been said to be associated with an element of heart failure in that the heart may tire pumping against increased periperal vascular resistance. Circulator Boot therapy rests the heart allowing it to tackle the vascular resistance with increased vigor once each therapy is over. To treat this phenomenon, one can transiently increase the anti-hypertension of the patient. Thus, if the patient is taking Diovan 40mg three times a day, 80mg might be given after the treatment and the blood pressure with a home sphygmomanometer. The EECP devices are designed to elevate the dicrotic notch (the point of closure of the aortic valve) as evidence of cardiac-assist. Unfortunately, this increases terminal systolic heart work. End-disatolic pumping does not do this.
  
  
• Bonetti PO, Holmes DR Jr, Lerman A, Barsness GW: Enhanced external counterpulsation for ischemic heart disease: what's behind the curtain? J Am Coll Cardiol 41:1918-25. 2003. Enhanced external counterpulsation (EECP) has been shown to reduce angina and to improve objective measures of myocardial ischemia in patients with refractory angina. Prospective clinical studies and large treatment registries suggest that a course of EECP is associated with prolongation of the time to exercise-induced ST-segment depression and resolution of myocardial perfusion defects, as well as with enhanced exercise tolerance and quality of life. With a growing knowledge base supporting the safety and beneficial clinical effects associated with EECP, this therapy can be considered a valuable treatment option, particularly in patients who have exhausted traditional revascularization methods and yet remain symptomatic despite optimal medical care. However, although the concept of external counterpulsation was introduced almost four decades ago, and despite growing evidence supporting the clinical benefit and safety of this therapeutic modality, little is firmly established regarding the mechanisms responsible for the beneficial effects associated with this technique. Suggested mechanisms contributing to the clinical benefit of EECP include improvement in endothelial function, promotion of coronary collateralization, enhancement of ventricular function, peripheral effects similar to those observed with regular physical exercise, and nonspecific placebo effects. This review summarizes the current evidence for a contribution of these mechanisms to the clinical benefit associated with EECP.
  
  
• Bonetti PO, Barsness GW, Keelan PC et al: Enhanced external counterpulsation improves endothelial function in patients with symptomatic coronary artery disease. J Am Coll Cardiol 41:1761-1768, 2003. Abstract: OBJECTIVES: The goal of this study was to examine the effect of enhanced external counterpulsation (EECP) on endothelial function. BACKGROUND: Enhanced external counterpulsation improves symptoms and exercise tolerance in patients with symptomatic coronary artery disease (CAD). However, the exact mechanisms by which this technique exerts its clinical benefit are unclear. METHODS: Reactive hyperemia-peripheral arterial tonometry (RH-PAT), a noninvasive method to assess peripheral endothelial function by measuring reactive hyperemic response in the finger, was performed in 23 patients with refractory angina undergoing a 35-h course of EECP. In each patient RH-PAT measurements were performed before and after the first, at midcourse, and the last EECP session. In addition, RH-PAT response was assessed one month after completion of EECP therapy; RH-PAT index, a measure of reactive hyperemia, was calculated as the ratio of the digital pulse volume during reactive hyperemia divided by that at rest. RESULTS: Enhanced external counterpulsation led to symptomatic improvement (?1 Canadian Cardiovascular Society class) in 17 (74%) patients; EECP was associated with a significant immediate increase in average RH-PAT index after each treatment (p < 0.05). In addition, average RH-PAT index at one-month follow-up was significantly higher than that before EECP therapy (p < 0.05). When patients were divided by their clinical response, RH-PAT index at one-month follow-up increased only in those patients who experienced clinical benefit. CONCLUSIONS: Enhanced external counterpulsation enhances peripheral endothelial function with beneficial effects persisting at one-month follow-up in patients with a positive clinical response. This suggests that improvement in endothelial function may contribute to the clinical benefit of EECP in patients with symptomatic CAD.
  
  
• Braith RW, Conti CR, Nichols WW, et al Enhanced External Counterpulsation Improves Peripheral Artery Flow-Mediated Dilation in Patients With Chronic Angina. A Randomized Sham-Controlled Study. Circulation. 2010 Oct 4. BACKGROUND: -Mechanisms responsible for anti-ischemic benefits of enhanced external counterpulsation (EECP) remain unknown. This was the first randomized sham-controlled study to investigate the extracardiac effects of EECP on peripheral artery flow-mediated dilation. Methods and Results-Forty-two symptomatic patients with coronary artery disease were randomized (2:1 ratio) to thirty-five 1-hour sessions of either EECP (n=28) or sham EECP (n=14). Flow-mediated dilation of the brachial and femoral arteries was performed with the use of ultrasound. Plasma levels of nitrate and nitrite, 6-keto-prostaglandin F1a, endothelin-1, asymmetrical dimethylarginine, tumor necrosis factor-a, monocyte chemoattractant protein-1, soluble vascular cell adhesion molecule, high-sensitivity C-reactive protein, and 8-isoprostane were measured. EECP increased brachial (+51% versus +2%) and femoral (+30% versus +3%) artery flow-mediated dilation, the nitric oxide turnover/production markers nitrate and nitrite (+36% versus +2%), and 6-keto-prostaglandin F1a (+71% versus +1%), whereas it decreased endothelin-1 (-25% versus +5%) and the nitric oxide synthase inhibitor asymmetrical dimethylarginine (-28% versus +0.2%) in treatment versus sham groups, respectively (all P<0.05). EECP decreased the proinflammatory cytokines tumor necrosis factor-a (-16% versus +12%), monocyte chemoattractant protein-1 (-13% versus +0.2%), soluble vascular cell adhesion molecule-1 (-6% versus +1%), high-sensitivity C-reactive protein (-32% versus +5%), and the lipid peroxidation marker 8-isoprostane (-21% versus +1.3%) in treatment versus sham groups, respectively (all P<0.05). EECP reduced angina classification (-62% versus 0%; P<0.001) in treatment versus sham groups, respectively. Conclusions-Our findings provide novel mechanistic evidence that EECP has a beneficial effect on peripheral artery flow-mediated dilation and endothelial-derived vasoactive agents in patients with symptomatic coronary artery disease.
  
  
• Brandjes DP, Buller HR, Heijboer H et al.:Compression stockings reduced the occurrence of post-thrombotic syndrome in proximal DVT. Lancet 349:759-62, 1977. Sized-to-fit, knee-length, graded compression stockings significantly reduced the occurrence of mild-to-moderate and severe post-thrombotic syndrome in patients with a first episode of proximal deep vein thrombosis. All patients had initially been treated with heparin for 5 or more days and then were given warfarin for three months. Comments: Prandroni et al (Ann Intern Med 125:1-7, 1996) remind us that 29% of patients with DVT develop the post-thrombotic syndrome within 8 years. Compression stockings are helpful but care must be exercised in not applying them to DVT patients with concomitant ischemia.
  
  
• Cheng JM, Valk SD et al: Usefulness of intra-aortic balloon pump counterpulsation in patients with cardiogenic shock from acute myocardial infarction. Am J Cardiol 104:327-32, 2009. Although intra-aortic balloon pump (IABP) counterpulsation is increasingly being used for the treatment of patients with cardiogenic shock from acute myocardial infarction, data on the long-term outcomes are lacking. The aim of the present study was to evaluate the 30-day and long-term mortality and to identify predictors for 30-day and long-term all-cause mortality of patients with acute myocardial infarction complicated by cardiogenic shock who were treated with IABP. From January 1990 to June 2004, 300 consecutive patients treated with IABP were included. The mean age of the study population was 61 +/- 11 years, and 79% of the patients were men. The survival rate until IABP removal after successful hemodynamic stabilization was 70% (n = 211). The overall cumulative 30-day survival rate was 58%. The 30-day mortality rate decreased over time from 52% in 1990 to 1994 to 36% in 2000 to 2004 (p for trend <0.05). Follow-up ranged from 0 to 15 years. In patients who survived until IABP removal, the cumulative 1-, 5-, and 10-year survival rate was 69%, 58%, and 36%, respectively. The adjusted predictors of long-term mortality were arrhythmias during the intensive cardiac care unit stay (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2 to 2.9) and renal failure during the intensive cardiac care unit stay (HR 2.5, 95% CI 1.3 to 5.1). After adjustment, treatment with primary percutaneous coronary intervention (HR 0.5, 95% CI 0.3 to 0.9) and coronary artery bypass grafting (HR 0.4, 95% CI 0.2 to 0.8) were associated with lower long-term mortality. In conclusion, in patients with acute myocardial infarction complicated by cardiogenic shock treated with IABP, the 30-day survival improved with time and an encouraging number of patients survived in the long term. Comments: The balloon requires a skillful physician to insert it. It blocks flow to the distal aorta. It is associated with complications at its insertion site and occasionally causes cholesterol emboli (for more on its complications, see http://www.circulatorboot.com/Newsletter/vol2numb3.html). The Circulator Boot enjoys freedom from these problems. In this article we see the prognosis of balloon patients treated for vascular shock remains guarded.
  
  
• Cheung AT, Savino JS, Weiss SJ:Beat-to-beat augmentation of left ventricular function by intraaortic counterpulsation. Anesthesiology 1996 Mar;84(3):545-54. Author's Abstract: BACKGROUND: Measuring the effects of intraaortic balloon counterpulsation (IABP) in single cardiac beats may permit an improved understanding of the physiologic mechanisms by which IABP improves the circulation. The objective of the study was to use trans- esophageal echocardiography in combination with hemodynamic measurements to test the hypothesis that IABP improves global left ventricular systolic function selectively in the IABP-augmented cardiac beats by acutely decreasing left ventricular afterload. METHODS: Twenty-seven studies in which the IABP-to-R wave trigger ratio was serially changed from 1:1, 1:2, 1:4, 0:1 (IABP off) and back to 1:1 were performed in 20 anesthetized cardiac surgical patients during IABP support. Left ventricular short-axis end-diastolic cross-sectional area, end-systolic area, mean end-systolic wall thickness, and ejection time were measured by transesophageal echocardiography at the midpapillary muscle level. Aortic pressure was measured simultaneously from the central lumen of the intraaortic balloon catheter. These measurements were used to calculate the fractional area change, end-systolic meridional wall stress, and heart rate-corrected velocity of circumferential fiber shortening. The echocardiographic and hemodynamic parameters of left ventricular preload, afterload, and systolic function immediately after balloon deflation (IABP-augmented cardiac beats) were compared to the parameters measured during nonaugmented cardiac beats to determine the beat-to-beat effects of IABP on left ventricular function. RESULTS: IABP-augmented cardiac beats had a decreased systolic arterial pressure and end-systolic meridional wall stress and increased diastolic blood pressure, fractional area change, and velocity of circumferential fiber shortening compared to nonaugmented cardiac beats. IABP did not cause significant beat-to-beat changes in heart rate, pulmonary artery diastolic pressure, or central venous pressure. The improvement in left ventricular systolic function associated with IABP-augmented cardiac beats correlated with the decrease in end-systolic meridional wall stress for that cardiac beat. CONCLUSIONS: Beat-to-beat echocardiographic and hemodynamic measurements performed in anesthetized cardiac surgical patients during IABP support demonstrated improved left ventricular systolic function and decreased left ventricular systolic wall stress in the cardiac beats immediately after balloon deflation. The relationship between left ventricular systolic function and left ventricular systolic wall stress during IABP support suggests that afterload reduction was an important mechanism by which IABP instantaneously improved circulatory function in anesthetized cardiac surgical patients. Comments: And these effects are found with the decompression of a small intraaortic balloon. See Dillon 1998 below for similar large effects seen with the decompression of the Circulator Boot.
  
  
• Chleboun GS, Howell JN, Baker HL, Ballard TN, Graham JL, Hallman HL, Perkins LE, Schauss JH and Conatser RR: Intermittent pneumatic compression effect on eccentric exercise-induced swelling, stiffness, and strength loss. Arch Phys Med Rehabil 76:744-749, 1995. Authors conclude that therapy is effective in temporarily decreasing the swelling and stiffness after exercise-induced muscle injury.
  
  
• Delis KT, Nicolaides AN, Wolfe JH, Stansby G: Improving walking ability and ankle brachial pressure indices in symptomatic peripheral vascular disease with intermittent pneumatic foot compression: a prospective controlled study with one-year follow-up. J Vasc Surg 31:650-61, 2000. Abstract: PURPOSE: Intermittent pneumatic foot compression (IPC(foot)) augments arterial leg inflow. It has been suggested that prolonged use of impulse leg compression at home might ameliorate claudication caused by peripheral vascular disease by improving collateral circulation. The purpose of this study was to determine the effect of IPC(foot) treatment on claudication distance and arterial hemodynamics in patients with intermittent claudication caused by peripheral vascular disease. METHODS: Thirty-seven patients with stable intermittent claudication were admitted to this prospective controlled study. Of these, 25 patients received IPC(foot) (>4 hr/d) for 4.5 months (group 1), and the other 12 patients acted as control patients (group 2). Both groups were advised to exercise unsupervised for a minimum of 1 hour daily and received aspirin (75 mg/d). Groups were matched for age, sex, risk factors, claudication distances, and ankle pressures at baseline. In each patient, initial claudication distance (ICD), absolute claudication distance (ACD), resting ankle brachial index (r-ABI), ankle brachial pressure index after exercise (p-eABI), and popliteal artery volume flow were measured at day 0, 2 weeks, and 1, 2, 3, and 4.5 months. On completion of the treatment period (4.5 months), both groups continued with aspirin (75 mg/d) and unsupervised exercise and were re-examined after 12 months. Data analysis is based on nonparametric statistics, the Wilcoxon signed ranks test, and the Mann-Whitney test for intragroup and intergroup comparisons, respectively. Results are expressed as median and interquartile ranges. RESULTS: Over the 4.5 months of active treatment, (1) median ICD in group 1 increased by 146% (P <.001), from 78 m (interquartile range, 65-102 m) at baseline to 191.5 m (interquartile range, 127-254 m); ICD did not significantly increase in group 2; (2) median ACD in group 1 improved by 106% (P <.001), from 124 m (interquartile range, 100-160 m) to 255 m (interquartile range, 149-398 m); no significant changes were documented in group 2; (3) median r-ABI in group 1 rose by 18% (P <.001), from 0.57 (interquartile range, 0.48-0.62) to 0.67 (interquartile range, 0.64-0.70); no improvement was noted in group 2; (4) median p-eABI in group 1 rose by 110% (P <.001), from 0.21 (interquartile range, 0.07-0.27) to 0.44 (interquartile range, 0. 36-0.52); no changes were noted in group 2; and (5) median popliteal artery volume flow in group 1 improved by 36% (P <.001), from 100 mL/min (interquartile range, 59-163 mL/min) to 136 mL/min (interquartile range, 99.5-173.4 mL/min); no significant changes were found in group 2. At 4.5 months, ICD, ACD, r-ABI, and p-eABI in group 1 were all significantly better than those in group 2 (P <.01). Twelve months' posttreatment, walking ability and ABIs in group 1 were not statistically different from those at 4.5 months and remained significantly better than those of control subjects. CONCLUSION: Intermittent pneumatic foot compression used at home for 4.5 months increases claudication distance by over 100%. Associated increases in r-ABI by 18%, p-eABI by 110%, and arterial calf inflow by 36% suggest an improved collateral circulation. Maximum benefit seems to be offered over the initial 3 months. Treatment benefits are maintained 1 year after treatment. A multicenter study is indicated to quantify actual benefits and to demonstrate cost effectiveness.
  
  
• Delis KT, Nicolaides AN, Labropoulos N, Stansby G: The acute effects of intermittent pneumatic foot versus calf versus simultaneous foot and calf compression on popliteal artery hemodynamics: a comparative study. J Vasc Surg 32:284-92, 2000.Irvine Laboratory for Cardiovascular Investigation and Research, Imperial College School of Medicine, Academic Vascular Surgery, St Mary's Hospital, Paddington, United Kingdom.INTRODUCTION: Intermittent pneumatic compression (IPC) is currently being investigated with respect to its effect on distal arterial volume flow in patients with peripheral vascular disease. Recently published data have shown a substantial acute enhancement in arterial calf inflow in response to IPC of the lower limb in both intermittent claudication and leg ischemia. PURPOSE: The aim of the study was to compare the immediate effects of intermittent pneumatic foot (IPC(foot)) versus calf (IPC(calf)) versus simultaneous foot and calf compression (IPC(foot+calf)) on popliteal artery hemodynamics in patients with intermittent claudication (Fontaine II) and in normal subjects, using duplex ultrasonography. For this purpose, 25 limbs of 20 healthy subjects (age range [mean], 51-74 [64] years) and 31 limbs of 25 claudicants (age range [mean], 56-81 [66.5] years; resting ankle-brachial indices, 0.38-0.75 [0.55]) were examined in the sitting position with and without IPC compression. RESULTS: Mean popliteal artery flow in healthy subjects increased by 98.8% on application of IPC(foot), 188% with IPC(calf), and 274% with IPC(foot+calf) (all P <.001). Mean flow in claudicants increased by 58% on application of IPC(foot), 132% with IPC(calf), and 174% with IPC(foot+calf) (all P ><.001). The mean velocity, peak systolic velocity, and end diastolic velocity displayed a pattern of change similar to that for volume flow in both groups. Pulsatility index decreased in both groups on application of IPC; the lowest values were generated with IPC(foot+calf). CONCLUSION: Of the three compression modes investigated, IPC(foot+calf) was the most effective means of acutely augmenting arterial calf inflow in arteriopaths and normals. The significant increase in end diastolic velocity and decrease in pulsatility index indicate that peripheral vasodilatation is the central mechanism in this impulse-related flow augmentation. Prospective trials are indicated to determine the clinical potential of the long-term effects of IPC(foot+calf) in patients with symptomatic peripheral vascular disease.Comments: Porter accompanied the first article (that above this one) with an editorial suggesting these authors were finally showing boots worked. In that article, they merely pumped on the foot. Here they are showing significantly more effect if they pumped on the foot and calf. If they increased their pumping rate and applied pressure in end-diastole, they would then have our Mini-Boot.
  
  
• Delis KT, Knaggs AL: Duration and amplitude decay of acute arterial leg inflow enhancement with intermittent pneumatic leg compression: an insight into the implicated physiologic mechanisms. J Vasc Surg 42(4): 717-25, 2005. PURPOSE: By acutely enhancing the arterial leg inflow, intermittent pneumatic leg compression (IPC) improves the walking ability, arterial hemodynamics, and quality of life of claudicants. We quantified the duration of acute leg inflow enhancement with IPC of the foot (IPC(foot)), calf (IPC(calf)), or both (IPC(foot+calf)) and its amplitude decay in claudicants and controls in relation to the pulsatility index, an estimate of peripheral resistance. These findings are cross-correlated with the features of the three implicated physiologic mechanisms: (1) an increase in the arteriovenous pressure gradient, (2) suspension of peripheral sympathetic autoregulation, and (3) enhanced release of nitric oxide with flow and shear-stress increase. METHODS: Twenty-six limbs of 24 claudicants with superficial femoral artery occlusion or stenoses (>75%) and 24 limbs of 20 healthy controls matched for age and sex, meeting stringent selection criteria, had their popliteal volume flow and pulsating index (peak-to-peak velocity/mean velocity) measured with duplex scanning at rest and upon delivery of IPC. Spectral waveforms were analyzed for 50 seconds after IPC delivery per 5-second segments. The three IPC modes were applied in a true crossover design. Data analysis was performed with the Page, Friedman, Wilcoxon, Mann-Whitney and chi2 tests. RESULTS: The median duration of flow enhancement in claudicants exceeded 50 seconds with IPC(foot), IPC(calf), and IPC(foot+calf) but was shorter (P < .001) in the controls (32.5 to 40 seconds). Among the three IPC modes, the duration of flow enhancement differed (P < .05) only between IPC(foot) and IPC(foot+calf). After reaching its peak within 5 seconds of IPC, flow enhancement decayed at rates decreasing over time (trend, P < .05, Page test), which in both groups were highest at 5 to 20 seconds, moderate at 20 to 35 seconds, and lowest at 35 to 50 seconds (P < .05, Friedman test). Baseline and peak flow with all IPC modes was similar between the two groups. Pulsatility index attenuation in claudicating limbs lasted a median 32.5 seconds with IPC(foot), 37.5 seconds with IPC(calf), and 40 seconds with IPC(foot+calf); duration of pulsatility index attenuation was shorter in the control limbs with IPC(foot) (30 seconds), IPC(calf) (32.5 seconds), or IPC(foot+calf) (35 seconds), yet differences, as well as those among the 3 IPC modes, were not significant. CONCLUSION: Leg inflow enhancement with IPC exceeds 50 seconds in claudicants and lasts 32.5 to 40 seconds in the controls. Peak flow occurs concurrently with maximal pulsatility index attenuation, within 5 seconds of IPC. Irrespective of group or IPC mode, the decay rate (%) of flow enhancement is highest within 5 to 20 seconds of IPC, moderate at 20 to 35 seconds, and lowest at 35 to 50 seconds. Since attenuation in peripheral resistance terminates with the mid time period (20 to 35 seconds) of flow decay, and nitric oxide has a half-life of <7 to 10 seconds, the study's data indicate that all implicated physiologic mechanisms (1, 2, and 3) are likely active immediately after IPC delivery (0 to 20 sec) and all but nitric oxide are effective in the mid time period (20 to 35 seconds). As the pulsatility index has returned to baseline, the late phase of flow enhancement (35 to 50 seconds) could be attributable to the declining arteriovenous pressure gradient alone. Comments: This study is included among our boot articles although the apparatus used is not a boot that covers and treats large portions of the leg but a cuff that compresses the calf and/or foot in pulses considerably slower than the Circulator Boot. Here again we see transient improvements in blood flow versus the long-lasting effects of Circulator Boot therapy.
  
  
• Delis KT, Nicolaides AN: Effect of Intermittent Pneumatic Compression of Foot and Calf on Walking Distance, Hemodynamics, and Quality of Life in Patients With Arterial Claudication. A Prospective Randomized Controlled Study With 1-Year Follow-up. Ann Surg 241: 431-441, 2005. Abstract: Summary Background Data: Perioperative mortality, graft failure, and angioplasty limitations militate against active intervention for claudication. With the exception of exercise programs, conservative treatments yield modest results. Intermittent pneumatic compression [IPC] of the foot used daily for 3 months enhances the walking ability and pressure indices of claudicants. Although IPC applied to the foot and calf together [IPCfoot+calf] is hemodynamically superior to IPC of the foot, its clinical effects in claudicants remain undetermined. Objective: This prospective randomized controlled study evaluates the effects of IPCfoot+calf on the walking ability, peripheral hemodynamics, and quality of life [QOL] in patients with arterial claudication. Methods: Forty-one stable claudicants, meeting stringent inclusion and exclusion criteria, were randomized to receive either IPCfoot+calf and aspirin[75 mg] (Group 1; n = 20), or aspirin[75 mg] alone (Group 2; n = 21), with stratification for diabetes and smoking. Groups matched for age, sex, initial [ICD] and absolute [ACD] claudication distances, pressure indices [ABI], popliteal artery flow, and QOL with the short-form 36 Health Survey Questionnaire (SF-36). IPCfoot+calf (120 mm Hg, inflation 4 seconds × 3 impulses per minute, calf inflate delay 1 second) was used for 5 months, =2.5 hours daily. Both groups were advised to exercise unsupervised. Evaluation of patients, after randomization, included the ICD and ACD, ABI, popliteal artery flow with duplex and QOL* at baseline*, 1/12, 2/12, 3/12, 4/12, 5/12* and 17/12. Logbooks allowed compliance control. Wilcoxon and Mann-Whitney corrected[Bonferroni] tests were used. Results: At 5/12 median ICD, ACD, resting and postexercise ABI had increased by 197%, 212%, 17%, and 64%, respectively, in Group 1 (P < 0.001), but had changed little (P > 0.1) in Group 2; Group 1 had better ICD, ACD, and resting and postexercise ABI (P < 0.01) than Group 2. Inter- and intragroup popliteal flow differences at 5/12 were small (P > 0.1). QOL had improved significantly in Group 1 but not in Group 2; QOL in the former was better (P < 0.01) than in Group 2. QOL in Group 1 was better (P < 0.01) than in Group 2 at 5/12. IPC was complication free. IPC compliance (=2.5 hours/d) was >82% at 1 month and >85% at 3 and 5 months. ABI and walking benefits in Group 1 were maintained a year after cessation of IPC treatment. Conclusions: IPCfoot+calf emerged as an effective, high-compliance, complication-free method for improving the walking ability and pressure indices in stable claudication, with a durable outcome. These changes were associated with a significant improvement in all aspects of QOL evaluated with the SF-36. Despite some limited benefit noted in some individuals, unsupervised exercise had a nonsignificant impact overall.
  
  
• de Simone G, di Lorenzo L, Ferrara LA, Costantino G, Fasano ML, Soro S, Mancini M: Noninvasive assessment of hemodynamic changes during therapy with nitrendipine in arterial hypertension. Jpn Heart J 28:73-84, 1987. Author's abstract: Changes in hemodynamic variables regulating systolic function were examined by M-mode echocardiography in 14 patients with long-duration primary uncomplicated hypertension treated with nitrendipine once daily (20 mg). At the end of treatment (8th week) blood pressure and peripheral resistance were greatly reduced (p less than 0.0001), while the indices of cardiac function (ejection fraction and cardiac index) showed significant increases (p less than 0.01). The variations in ejection fraction were analyzed by multiple linear regression and were mainly influenced by the decrease in end-systolic stress (contribution: 60%). At baseline, despite no radiographic or clinical signs of heart failure, 6 of the studied patients showed impaired systolic function, likely due to the strength of other variables (age, risk factors); in those patients, systolic function was clearly enhanced at the end of treatment, while no change was found in patients with initial normal pump function. Changes in cardiac output were due to a significant increase in heart rate in patients with normal pump function and to improved stroke volume in the others. Left ventricular mass index was slightly reduced (p less than 0.005), primarily because of the reduction in end-diastolic volume (p less than 0.01). When analyzed by the 2 subgroups (with or without impaired systolic function), the left ventricular mass index appeared to be significantly reduced only in those patients with normal basal pump function. This difference was most likely due to the different effects of treatment on end-diastolic volume.Comments: This article is included because, like the article below (Dillon 1998) describing the hemodynamic effects of booting, the importance of diastolic unloading is emphasized.
  
  
• Dick P, Mlekusch W et al: Decreasing incidence of critical limb ischemia after intra-aortic balloon pump counterpulsation. Angiology 60(2):235-41, 2009. The authors investigated the incidence of critical limb ischemia (CLI) in 187 patients with intra-aortic balloon pump (IABP) support during a 6-year study period and determined risk factors and long-term outcome (median 5 years) after discharge from a cardiac intensive care unit. Cardiogenic shock following acute myocardial infarction was the predominant cause of IABP support. CLI occurred in 10% of the patients after IABP implantation. Nevertheless, in light of the overall high mortality in this patient population, CLI seems not a primary concern. Furthermore, its incidence significantly decreased during recent years. Duration of IABP support was a significant predictor for CLI.Comments: No such problems with the Circulator Boot.
  
  
• Dillon RS: An end-diastolic air compression boot for circulation augmentation. J Clin Engineering 3:63, 1980. Description of Circulator Boot systems and comparison with other vascular pneumatic boots.
  
  
• Dillon RS: Effect of therapy with pneumatic end-diastolic leg compression boot on peripheral vascular tests and on the clinical course of peripheral vascular disease. Angiology 31:614-638, 1980. The Circulator Boot is a new end-diastolic pneumatic leg compression device. This report describes its effect on 6 normal young people, 8 ambulatory patients with mild peripheral arterial disease, and 21 consecutive patients (of whom 18 were hospitalized) with severe peripheral arterial disease in 25 legs. The courses of 4 patients are discussed in detail. Significant beneficial effects were documented by subcutaneous PO2 levels, pulse volume measurements, ankle blood pressure measurements, and Doppler ultrasound tracings. Twenty-two of the 25 severe legs benefited clinically from therapy. Immediate therapeutic effects from the boot are attributed to decreases in venous pressure, interstitial fluid pressure, vasoconstriction, and viscosity, and to increases in cardiac output, pulse pressure, and fibrinolysis in the treated leg. The long-term beneficial effects of boot therapy may be related to improved collateral flow and to the rechanneling of obstructed vessels. Comments: The baseline ABI was under 0.5 in the dorsalis pedis in 17 legs and in the posterior tibial in 15 legs. Significant improvements were seen in all of the noninvasive vascular tests measured:

  Table 1: Summary of Vascular Tests

  Means +/- Standard Deviations

  ---

  Increases in BP mm Hg	Dorsalis Pedis 43.1+/-11.2 P<0.001	Post. Tibial 32.1+/-11.1 P<0.01
  Increases in ABI	Dorsalis Pedis 31.0+/-8.4 P<0.01	Post. Tibial 23.7+/-8.4 P<0.02
  Increases in Doppler Amplitudes	Dorsalis Pedis 10.8+/-2.1 P<0.001	Post. Tibial 13.7+/-2.7 P<0.001
  Increases in Ankle Oscillometry Indices	0.8+/-0.12 P<0.001) -	-
  Number of Treatments	47.7+/-43.7	-
  Duration of Treatments	5.8+/-6.6weeks	-

  ---

  The patients were treated as long as needed to address successfully their clinical problems. The effects of a single treatment on the baseline PO2 levels were also reported; persentages of 26 (in relatively normal skin) to 1800% (in obviously ischemic skin) were seen. As serial angiograms posed significant risks to the patients, they were only done in occasional patients; some of these angiograms are shown in our case history section. The equipment and techniques have been subsequently improved. Osteomyelitis was not always easily cured with systemic antibiotics and boot alone. As noted below the addition of locally injected antibiotics proved beneficial (Dillon, 1986).
  
  
• Dillon RS: Treatment of resistant venous stasis ulcers and dermatitis with the end-diastolic pneumatic compression boot (TM). Angiology 37: 47-56, 1986. Abstract: The end-diastolic pneumatic compression boot was used to treat 17 patients with difficult or refractory stasis dermatitis and ulcers. Decreases in induration, pigmentation, and palpable thrombi were observed and all patients were improved or healed. The boot treatment allowed effective local administration of antibiotics on gauze wrappings. Removal of the latter after treatments provided a means of nonsurgical debridement. Healing was maintained by periodic outpatient boot treatments in patients with close follow-up. Ulcers recurred in patients lost to follow-up but again responded to boot treatment. One diabetic man with knee contractures and both severe venous and arterial disease relapsed repetitively and lost both legs in spite of bilateral femoral-popliteal bypasses and his boot treatments. Comments: Venous stasis ulcers are really ischemic lesions in which the blockage is on the venous side, rather than the arterial side. Booting restores venous blood flow in promoting the dissolution of the venous thrombi and in reducing induration and edema. Arterial vascular tests significantly improved with the boot treatments in the seven patients who had concomitant arterial disease. Pulmonary emboli were not a problem. Care must be taken, however, in being sure that new large clots are not present in the larger veins at the start of therapy.
  
  
• Dillon RS: Successful treatment of osteomyelitis and soft tissue infections in ischemic diabetic legs by antibiotic injections and the end-diastolic pneumatic compression boot. Ann Surg 204: 643-649, 1986. For abstract, see our library on "Cellulitis, Osteomyelitis and Sepsis."
  
  
• Dillon RS: Treatment of osteomyelitis in diabetic foot with systemic and locally-injected antibiotics and the end-diastolic pneumatic compression boot - Case studies. Vasc Surg (Westerminister Press) 24: 682-695, 1990. Abstract:The treatment of 35 patients for 43 episodes of osteomyelitis in the distal lower extremity is summarized and the long-term courses of three patients are illustrated in detail. Systemic antibiotics were used both to help control infection in the foot and to prevent septic emboli. The systemic antibiotics were given by the oral route alone (16 episodes), by the parenteral route alone (4 episodes), or by both oral and parenteral routes (22 episodes). Local foot treatments included injections of antibiotics into the infected areas of the foot, multielectrolyte-antibiotic foot soaks, and the end-diastolic pneumatic compression boot. X-ray evidence of osteomyelitis was found one to four weeks after it was clinically suspected and was associated with an improvement in the clinical status of the foot. Osteomyelitis was not considered an indication for amputation. The osteomyelitis lesions healed and foot structure and function were maintained. Comments: Lost in the editorial process of this manuscript was the fact that these were not selected for this report because of their successful treatment; they were consecutive referrals who were found to have osteomyelitis. Patients with severe ischemia and infection likely present with gangrene. Patients with x-ray changes of osteomyelitis must have sufficient blood flow to allow the serial dissolution and remodeling processes characteristic of osteomyelitis. These patients, hence, do have some blood flow and with the techniques described may almost all be cured. It is to be appreciated, however, that most all these patients had significant ischemia: 26 feet had no palpable pulses, 4 had one palpable pulse while 12 feet had both the dorsalis pedis and posterior tibial palpable. The mean of the ABI in the dorsalis pedis and posterior tibial was under 0.6 in 13 feet and under 0.4 in 6 feet. Sterilization of the drainage, healing of the associated ulcers and normalization of the sed rate point to a success regardless what the x-ray may be showing. Allowed some time (weeks to months), the involved bone may be conserved without surgery. How do other centers fare with such cases? See Armstrong et al for the Texas Wound Classification System in our Epidemiology library; close to 100% of our patients would have had amputations in their institution. How is our success interpreted by some reviewers? Those in the Georgia Medicare system, for example, call us investigational, but they also ignore the success reported at the Mayo Clinic. View original article in Vascular Surgery and/or View 60 cases of osteomyelitis successfully treated by these techniques
  
  
• Dillon RS: Optimizing external cardiac-assist compressions in patients with atrial fibrillation by anticipating the next beat. Angiology 47: 123-129, 1996. Comments: This is a computer analysis of the EKG strips taken from 30 patients with atrial fibrillation. An empirical formula was developed and tested on the computer to significantly improve the efficiency of the Circulator Boot in assisting the hearts of patients with atrial fibrillation. This empirical formula has been incorporated into the monitor of the Circulator Boot systems now in production.
  
  
• Dillon RS: Fifteen years of experience in treating 2177 episodes of foot and leg lesions with the Circulator Boot-Results of treatments with the Circulator Boot.Angiology 48, Number 5, Part 2: S17-S34, 1997. Abstract: Objective: To determine the clinical effectiveness of the end-diastolic pneumatic compression boot and of local antibiotics in treating limb lesions associated with diabetes and peripheral arterial, venous and neuropathic disease. Research Design and methods: Office and hospital data were kept over 15 years on 2177 episodes of leg problems classified by the Wagner method for 1514 legs of 1035 patients largely referred because of failure of standard therapies. The fate of the untreated legs served as a control when possible. Results: Healing or improvement of treated legs was seen above that in the literature in all Wagner categories and was significant (P<0.001) compared to the "control" leg which deteriorated in 38.7% of patients. Significant risk factors against a successful outcome included smoking, inability to walk, increased home distance from the boot center, loss to treatment, hemodialysis, a Wagner 4-5 classification, inoperable iliac occlusions, vascular surgical procedures before or after referral for boot therapy and an aggressive vascular surgeon. Neuropathy allowed successful treatment of lesions nondiabetic patients could not tolerate. Relapse was significantly more frequent in ASO patients with diabetes than without diabetes and in patients with neuropathy than those with ASO. Diabetes did not affect the relapse rate in stasis disease. The overall percentage of legs having major amputations was low: 2.46% for diabetic legs at the initial treatment episode, 1.6% at the time of a relapse and 4.14% after seeking treatment elsewhere. For nondiabetic patients, the respective risks were similar: 2.0%, 1.18% and 2.88%. Comments: This study may be the largest and the longest in the medical literature. It shows that long lasting benefits may result from therapy with the Circulator Boot systems. At medical meetings, our salesmen have been presented with the criticism that the study is a one-man show and that it is uncontrolled and retrospective in nature. In answer to these criticisms, one might make many observations. An one-author study is more likely to be uniform in technique (treatment technique is described in the companion article). The study actually has multiple controls: (a) the patients largely had had "control" or standard therapies and were referred after they had failed; (b) the fate of the good leg served as a control in many and it broke down while the presenting diseased leg healed; (c) reviewers for the insurance companies and Medicare could deny payments if the therapies were not shown to be beneficial and necessary; and (c)the referring physician frequently maintained surveillance of these patients and could have discontinued the boot therapy if they saw no progress. Finally, it should be appreciated that these treatments were accomplished in real life situations: the community hospital, the doctor's office and the nursing home... not in a clinical research ward. The treatment works in real life. Full text of this article
  
  
• Dillon RS: Patient assessment and examples of a method of treatment-Use of the Circulator Boot in peripheral vascular disease. Angiology 48, Number 5, part 2: S35-S58, 1997. Summary: Effective peripheral blood flow is positively related to cardiac output and gravity (part dependent) and inversely related to gravity (part elevated), venous pressure, interstitial fluid pressure, degree of peripheral neuropathy, arteriosclerotic and thrombotic arterial occlusions, and infection. These factors are considered in the operation of the end-diastolic pneumatic boot in the treatment of illustrative patients with lymphedema, venous stasis disease, peripheral arteriosclerosis obliterans, peripheral neuropathy, cellulitis and osteomyelitis and the failing heart. A method of treatment that includes the use of the boot and the injection of local antibiotics is described.Full text of this article
  
  
• Dillon RS: Improved hemodynamics shown by continuous monitoring of electrical impedance during external counterpulsation with the end-diastolic pneumatic boot and improved ambulatory EKG monitoring after 3 weeks of therapy. Angiology 49: 523-535, 1998. Abstract: Six normal subjects and 12 patients with clinical angina and significant ST depressions during baseline ambulatory cardiac monitoring were given a single treatment with the end-diastolic pneumatic compression boot, the Circulator Boot - TM. With the use of continuous electrical impedance measurements, multiple hemodynamic variables were followed in five situations: (1) baseline before pumping; during end-diastolic pumping (2) on both legs after every heartbeat, (3) on one leg after every heartbeat and (4) on both legs on alternate beats; and (5) during pumping on both legs during every systole. Both an increase in venous return and a reduction in afterload likely contributed to significant increases in cardiac output (51.1(33.6%), stroke volume (52.1(35.6%), dZ/dT (72.0(68.1%), cardiac index (51.2(33.8%) and acceleration index (50.7(62.2%) during end-diastolic pumping on both legs after every heartbeat. A crucial role for afterload reduction was implicated by opposite effects on CO, CI, dZ/dT and SV during systolic pumping. Again, reductions (or lack of an increase) in ventricular ejection time and/or the pre-ejection period suggested a decrease in afterload during end-diastolic pumping. Pumping on one leg after every heartbeat and on both legs on alternate heartbeats was also effective but less so. After the initial study, the patients were given 14 additional end-diastolic treatments to both legs over three weeks. A clinical benefit was shown by symptomatic improvement in all patients along with a significant reduction in the amount and duration of the RST abnormalities in their ambulatory heart monitoring (P=0.012). Comments: How does the Circulator Boot work, we are commonly asked. Here we see that it is a significant cardiac-assist device that improves stroke volume, cardiac output and, presumably, coronary blood flow. Patients with advanced heart failure commonly have cyanosis of their fingers and toes which may disappear when heart function improves. In contrast to the aortic balloon, the Circulator Boot does not need specialized individuals to apply it; it may be promptly applied, removed and applied again; it has no vascular complications; it does not block blood flow to the lower body; it assists venous return; it stimulates the elaboration of prostacyclin, nitric oxide and fibrinolysins; and it has superior effects on systemic hemodynamics. Indeed, the aortic balloon commonly changes hemodynamic data little. Prolonged therapy with the Circulator Boot, on the other hand, is more confining. The latter disadvantage may be approached by alternating legs, sedating the patient and/or removing the boot intermittently. It is interesting to consider the physiology of the Circulator Boot historically and to contrast the findings reported here with those of Frank in 1895 and Starling in 1914. Frank noted that an increase in preload increased the force of contractions of the isolated frog heart. Starling utilized a canine heart-lung preparation in which the lungs were artificially ventilated (potentially preventing pulmonary congestion as right atrial filling pressures were increased). While allowing aortic pressure to increase about 5%, he found perhaps a 70% increase in stroke volume after a 53% increase in right atrial filling pressure and provided us with the now classic concept that cardiac output increases to a point as the heart fibers are stretched with increases in ventricular filling (Patterson SW, Piper H, Starling EH: J Physiol 48:465, 1914). Again, he noted increases in stroke volume, albeit less prominent, when ventricular volume was increased by increasing peripheral vascular resistance and aortic blood pressure. Two potentially detrimental effects of his experiment are to be noted, however. First, ventricular dilatation significantly increases the force each heart fiber must exert to obtain a given intraventricular pressure; heart work increases and heart efficiency decreases. Second, coronary artery perfusion occurs predominantly in diastole and increased diastolic ventricular pressures decrease coronary perfusion. While therapy with the Circulator Boot does increase preload, the increase in preload is shown not to be crucial. In contrast to Frank and Starling, Circulator Boot therapy increases stroke volume by decreasing afterload while at the same time decreasing heart work and maintaining or ?increasing coronary perfusion. The clinical implications of these observations are obvious. It is apparent, for example, that the failing patient in intensive care may be better served with Circulator Boot therapy than a fluid challenge.... and that the benefit may be easily documented both rapidly and non-invasively with an electrical impedance monitor
  
  
• Dillon RS: Pathophysiology of diabetic foot lesions and their treatment with the Circulator Boot-TM. Chapter 13 in "The Wound Management Manual" pages 141-211. Bok Y. Lee editor. McGraw-Hill 2005.
  
  
• Erdling A, Bondesson S, Pettersson T, Edvinsson L.: Enhanced external counter pulsation in treatment of refractory angina pectoris: two year outcome and baseline factors associated with treatment failure. BMC Cardiovasc Disord 18;8:39, 2008. Abstract: BACKGROUND: Enhanced external counter pulsation (EECP) is a non-invasive treatment option for patients with refractory angina pectoris ineligible to further traditional treatment. The aim of this study was to evaluate the effect of EECP on patients at a Scandinavian medical centre and to investigate if outcome can be predicted by analysing baseline factors. METHODS: 86 consecutive patients (70 male, 16 female) were treated with EECP and followed for two years post treatment. Canadian cardiovascular society (CCS) class was analysed, and medication and adverse clinical events were researched prior to EECP, at the end of the treatment, and at six, 12 and 24 months thereafter. Patients responding to therapy by improving at least one CCS class were compared with those who failed to respond. Any differences in background factors were recorded and analysed. RESULTS: 79% of the patients responded to therapy by improving at least one CCS class. In general, the CCS class improved by one class after EECP treatment (3.05 before versus 2.14 after treatment). A total of 61.5% of the initial responders showed sustained improvement at the 12 month follow-up while 29% presented sustained improvement after 24 months. Treatment was most effective among patients suffering from CCS class III-IV angina pectoris, while patients suffering from CCS class II angina pectoris improved transiently but failed to show sustained improvement after the 12 month follow-up. Diabetes mellitus and calcium channel antagonists were more common among the non-responders (p < 0.05). CONCLUSION: This study confirms the safety and efficiency of EECP as a treatment option for patients suffering from refractory angina pectoris. The therapy is most beneficial in patients suffering from severe angina (CCS III-IV) while sustained response to therapy could not be verified among patients suffering from CCS class II angina pectoris.
  
  
• Eze AR, Comerota AJ, Cisek PL, Holland BS, Kerr RP, Veeramasuneni R and Comerota Jr. A|J: Intermittent calf and foot compression increases lower extremity blood flow. Am J Surg 172:130-135, 1996. Authors' conclusions: Measured in the sitting position, the resting popliteal artery blood flow and foot skin perfusion are greater in patients with SFA occlusion compared to normal volunteers. Following compression, popliteal artery blood flow and skin perfusion increased in both groups, but relatively more in volunteers. Increases in popliteal artery blood flow are significantly higher with calf compression than with foot compression for both groups. A patent SFA allows for additive increases in popliteal artery blood flow with simultaneous foot and calf compression in normal persons, whereas this is not observed in patients. However, the increases in foot skin perfusion in patients with an occluded SFA parallel the increases shown in normal volunteers, with separate and simultaneous foot and calf compression. Comments: Here a 22cm calf cuff and a 12cm foot cuff were used to inflate to a pressure of 120 mm Hg over 0.3 seconds, hold the pressure 10 seconds and then release and remain deflated for 20 seconds. The patients had ABI's in the supine position of 0.55 to 0.75. Hypothesizing a brachial artery pressure of 140 mm Hg, their ankle blood pressures might have varied from 77 to 105 mm Hg. In the sitting position with a vertical calf, the ankle is perhaps 36 inches below the aortic root or 30 inches below it when the foot is on a "low stool" (the top of the calf cuff, of course, is closer to the heart and is less benefited by the following calculations). As 30 inches of water pressure equals 55 mm Hg pressure, the perfusion pressure at the ankle was the sum of the two or 77+55 to 105+55 mm Hg. Thus, 132 to 160 mmHg pressure was opposed by the 120 mm pressure of the inflated cuffs in their study. For most patients in their study, the cuff pressure was not sufficient to either obstruct or reverse arterial inflow; as shown below, the same may not be true for patients with more severe ischemia. Here, the pressure was clearly sufficient to expel a considerable volume of venous blood and, on release of the cuffs, markedly increase the distal arterial/venous gradient.
  
  

  The data below shows what happens, however, when a leg is very ischemic and has a progressive drop in systolic pressure from the groin to the foot, a boot encompassing the leg from the groin to the ankle is used, and the boot is inflated to 55 mm Hg for periods of several seconds. These tracings were obtained from a patient referred to the Bryn Mawr Circulator Boot Clinic after his leg had deteriorated elsewhere after treatments with a boot designed for treating lymphedema and venous stasis. In obtaining this study, a Circulator Boot was utilized setting the delay time to zero and the compression time to one second; in effect the boot continued to compress the leg until the boot switch was manually turned off. The boot, hence, could be alternately inflated and deflated for any desired time period. The graph reads from right to left. A baseline period is followed by a series of compressions and decompressions lasting several seconds each. The subcutaneous PO2 level is seen to progressively drop. The boot was then set to deliver end-diastolic compressions and the PO2 tension is seen to progressively rise. Such measurements are not necessary in clinical practice as improper pumping will produce pain and numbness in the distal extremity. If such pain occurs with end-diastolic pumping, the Circulator Boot is set to allow more arterial inflow by decreasing the compression rate from 1:1 to 1:2 or 1:3.

  Subcutaneous PO2 Changes in an Ischemic Leg as Influenced by End-diastolc Compressions versus Compressions Lasting a Few Seconds

• Filip, John: APWCA Case Study #2: Application of end-diastolic pneumatic compression therapy with the Circulator Boot. Podiatry Management 26(9): 149-159, 2007. No abstract available. Illustrated case report in which lady with advanced lesions of both legs and feet spared bilateral amputations.
  
  
• Filip JR, Dillon RS: Treatment of end-stage "trash feet" with the end-diastolic pneumatic boot. Angiology 59(2):214-9, 2008. This study reassessed the clinical effect of Circulator Boot (CB) therapy in patients with cholesterol embolization syndrome (CES) of the lower extremities. The medical records were reviewed of 27 patients consecutively referred to the Bryn Mawr Wound Care and Vascular Center with CES who had not responded to previous therapies. All patients with CES referred from January 1, 1997, to September 19, 2005, were followed up and included in the study. The alternate therapy offered for most patients at the time of referral was limb amputation. The median age of the patients was 65 years (age range, 46-84 years) at the time of diagnosis. Healing of CES was observed after a median interval of 11 months (range, 3-32 months) following the initiation of CB therapy. The total number of legs treated was 41. Of 41 legs, 33 (81%) were totally healed, 6 (15%) improved, and 2 (5%) were amputated. After an initial period of improvement, one patient died a month later of causes unrelated to CES or CB therapy. Another patient improved and discontinued treatment before he was totally healed. Cholesterol embolization syndrome is seen predominantly in patients following cardiac or vascular procedures but may occur spontaneously. The CB seems to be the only effective noninvasive therapy for CES. Early initiation of therapy is essential to minimize tissue loss and patient discomfort.
  
  
• Fisher CG, Blachut Pa, Salvian AJ, Meek RN and O'Brien PJ: Effectiveness of pneumatic compression devices for the prevention of thromboembolic disease in orthopaedic truama patients: a prospective randomized study of compression alone versus no prophylaxis. J Ortho Trauma 9:1-7, 1995. Sequential leg sleeves cycling at 71 second intervals with each compression lasting 11 seconds...ankle 45mm Hgk, calf 35-40mm Hg, and thigh 25mm Hg. Among patients with hip fractures, TE events occurred in 12% of controls and in 4% of treated patients (P < 0.02). No significant difference in pelvic fracture patients.
  
  
• Gilbart MK, Oglivie-Harris DJ, Broadhurst C and Clarfield M: Anterior tibial compartment pressures during intermittent sequential pneumatic compression therapy.Am J Sports Med 23:769-772, 1995. Abstract: We studied the anterior tibial compartment pressures during the application of a JOBST sequential intermittent pneumatic compression device on 5 healthy human volunteers (10 legs). Intracompartmental pressures were measured using a slit catheter. The measurements of interstitial pressures were increased for approximately 120 seconds during each cycle. Pressure measurements in the inflated pressure sleeve varied less than 10% with the measured anterior compartment pressures during intermittent pneumatic compression therapy. This intermittent pneumatic pressure device may elevate intramuscular pressure significantly above that necessary to render muscle ischemic. However, these periods of pressure elevation are not long enough to produce any significant adverse effects, and the beneficial effects of decreased edema fluid may be safely realized.
  
  
• Ginsberg JS, Brill-Edwards P, Kowalchuk G, Hirsh J: Intermittent compression units for the postphlebitic syndrome. A pilot study. Arch Intern Med 149: 1651-2, 1989. The postphlebitic syndrome is a common affliction with limited therapeutic options. Patients who fail to respond to treatment with graded elastic compression stockings often develop a chronic pain syndrome manifested by intractable pain and swelling. Because lymphedema, a condition also associated with leg pain and swelling, has been successfully treated by intermittent compressive therapy with an extremity pump, we conducted a pilot study of compressive therapy in patients with severe postphlebitic syndrome. All five patients studied had dramatic improvement in symptoms and functional status without side effects. Although a large randomized trial is needed to properly evaluate compressive therapy, it appears to be very effective in selected patients.
  
  
• Goldman BS, Hill TJ, Rosenthal GA, Scully HE, Weisel RD and Baird RJ: Complications associated with use of the intra-aortic balloon pump. Can J Surg 25:153-156, 1982. 299 patients between 1977 and 1979. Overall complication rate of 24.4% . Patients with inoperable ASHD or severe left ventricular dysfunction especially at risk (complications in 47.6%). Vascular complications: aortic dissection 1.3%, perforation 0.3%, bleeding at site 2.3%, femoral or iliac occlusion 1%, thromboembolism 4.3% and limb ischemia 5.4%. Infections developed at the femoral site in 5.7% and systemic infection developed in 2.3%.
  
  
• Gruenes J, Nelson JP et al: An evaluation of the efficacy of the Circulator Boot in altering hemodynamics of the ischemic lower extremity and foot. Midwest Podiatry Conference 2005 (Chicago). Barry University School of Grad Med Sci. Every pumped extremity had increased perfusion after four weeks with an average increase of 43%. Twelve of 13 long term ulcers healed during the study.
  
  
• Han JH, Leung TW, Lam WW et al:: Preliminary Findings of External Counterpulsation for Ischemic Stroke Patient With Large Artery Occlusive Disease. Stroke 39:1340-3, 2008. BACKGROUND AND PURPOSE: We aimed to investigate the feasibility and therapeutic effect of external counterpulsation (ECP) in ischemic stroke. METHODS: The trial was a randomized, crossover, assessment-blinded, proof-of-concept trial. ECP treatment consisted of 35 daily 1-hour sessions. Patients were randomized to either early (ECP weeks 1 to 7 and no ECP weeks 8 to 14) or late group (no ECP weeks 1 to 7 and ECP weeks 8 to 14). Primary outcomes were an overall change in National Institutes of Health Stroke Scale (NIHSS) and cerebral blood flow estimated by color velocity imaging quantification. Secondary outcomes were change in NIHSS, color velocity imaging quantification, favorable functional outcome (modified Rankin scale, 0 to 2), and stroke recurrence at weeks 7 and 14, respectively. RESULTS: Fifty patients were recruited. At week 7, there was a significant change in NIHSS (early 3.5 vs late 1.9; P=0.042). After adjusting for treatment sequence, ECP was associated with a favorable trend of change in NIHSS of 2.1 vs 1.3 for non-ECP (P=0.061). Changes of color velocity imaging quantification were not significant but tended to increase with ECP. At week 14, a favorable functional outcome was found in 100% of early group patients compared to 76% in the late group (P=0.022). CONCLUSIONS: ECP is feasible for ischemic stroke patients with larger artery disease.
  
  
• Henry WL, Morganroth J et al: Relation between echocardiographically determined left atrial size and atrial fibrillation.Circulation 53:273-279, 1976. In an attempt to define quantitatively the relation between left atrial size and atrial fibrillation, echocardiography was used to study 85 patients with isolated mitral valve disease, 50 patients with isolated aortic valve disease, and 130 patients with asymmetric septal hypertrophy. In all three groups of patients, atrial fibrillation was rare when left atrial dimension was below 44 mm (3 of 117 or 3%) but common when this dimension exceeded 40 mm (80 of 148 or 54%). In addition, when left atrial dimension exceeds 45 mm, cardioversion, while initially successful, is unlikely to produce sinus rhythm that can be maintained at least six months. These data suggest that left atrial size is an important factor in the development of atrial fibrillation and in determining the long term result of cardioversion. The pathophysiologic mechansim most consistent with this is that a chronic hemodynamic burden initially produces left atrial enlargement which in turn predisposes to atrial fibrillation. Only prospective studies will determine definitively whether these observations will be useful in decisions concerning prophylactic anticoagulation and elective cardioversion. Comments: Left atrial size plays a role likely in the initiation and reoccurrence of atrial fibrillation. It is possible that the conversion of some of our boot patients with recent onset atrial fibrillation to normal sinus rhythm is due to the marked reduction in afterload associated with boot therapy allowing the left ventricle to empty more readily and decreasing any back flow into the left atrium.... atrial size may be reduced.
  
  
• Henein MY, Das SK, O'Sullivan C, Kakkar VV, Gillbe CE, Gibson DG: Effect of acute alterations in afterload on left ventricular function in patients with combined coronary artery and peripheral vascular disease. Heart 75(2): 151-8, 1966. Abstract: Objective: To assess the effect of acute alterations in afterload by aortoiliac clamping, during peripheral vascular surgery, on left ventricular function. Design: Prospective examination of the left ventricular long axis and transmitral Doppler flow preoperatively and intraoperatively; before aortic clamping, during clamping and 5 min, 15 min, and 5 days after unclamping. Setting: A tertiary referral centre for cardiac and vascular disease equipped with invasive and non-invasive facilities. Patients: 20 patients (11 men; mean (SD) age 61 (8) years) with significant aortoiliac disease and documented coronary artery disease and 21 normal controls of similar age. Results: Preoperatively: long axis function was abnormal compared with that in normal controls. In systole total long axis excursion and peak shortening rate were reduced, onset of shortening delayed, and there was pre-ejection lengthening (P<0.001). In diastole there was abnormal shortening during isovolumic relaxation, delaying the onset of long axis lengthening (P><0.001). Peak lengthening rate was also reduced and A wave excursion increased (P><0.001). Transmitral Doppler showed increased A wave velocity and reduced E/A diastolic flow velocities ratio (P><0.001). Intraoperatively: preclamping results did not differ from those before operation. With clamping the extent of systolic and diastolic abnormalities promptly increased as to a lesser extent did those of transmitral flow velocity, although heart rate and blood pressure did not change significantly. Total long axis excursion and A wave amplitude were more reduced by aortic than iliac clamping, whereas the onset of lengthening was more delayed and the lengthening velocity more reduced with iliac clamping. Some 5 min after unclamping systolic long axis function had already returned towards normal; total excursion increased, as did peak shortening rate, and the onset of shortening became less delayed (P><0.001). In diastole the delayed onset of lengthening regressed, its lengthening velocity increased, and A wave excursion fell (P><0.001). Early diastolic transmitral flow velocity also increased. This improvement in systolic and diastolic long axis function had progressed 15 min after unclamping but showed no further change at 5 days. At 5 days after operation, however, systolic and diastolic measurements had improved compared with those preoperatively. Conclusion: Resting left ventricular long axis function is abnormal in patients with combined coronary artery and peripheral vascular disease. It is unaffected by anesthesia but deteriorates with aortic or iliac clamping, although blood pressure remains unchanged. It promptly improves with unclamping after successful peripheral arterial reconstruction. Thus, even in apparently stable coronary artery disease, resting subendocardial function is labile, showing pronounced alterations with changing after-load, even when arterial pressure itself does not change. Comments: Changes in after-load can rapidly be effected in the Circulator Long-Boot. Setting the Circulator Boot heart monitor to deliver boot compressions during systole increases after-load. Setting the monitor to deliver compressions in diastole and to release the leg in presystole decreases after-load. Similar hemodynamic changes are seen here with clamping the aorta or iliac arteries. See Dillon 1998 above.
  
  
• Ho CK, Sun MP, Au TW, Chiu CS: Pneumatic pump reduces leg wound complications in cardiac patients. Asian Cardiovasc Thorac Ann 14:452-7, 2006. Leg wound complications at the site of vein harvest for coronary artery bypass graft, although infrequent, cause significant morbidity. Pneumatic pressure therapy is valuable in venous and lymphatic diseases, but its usefulness after leg vein harvest has not been determined. A prospective randomized controlled trial was conducted on 200 patients, half of whom had sequential pneumatic leg pump therapy postoperatively. Wound healing, extent of lower limb edema, patient satisfaction, and the financial implications of pneumatic pressure therapy were assessed. In the study group, 71 patients had satisfactory wound healing vs. 23 in the control group. The leg wound infection rate in the study group was 3% vs. 15% in the control group ( p = 0.003). Lower limb edema was significantly reduced in the study group in the early postoperative period ( p < 0.05), and the mean postoperative length of hospital stay was reduced by 2.6 days in patients given pneumatic pressure therapy ( p = 0.003). The sequential pneumatic leg pump is an effective, inexpensive, and convenient device that reduces leg wound complications after coronary artery bypass grafting. Comments: Ascending TEDS, of course, would be contraindicated if edema is associated with ischemia. Therapy with the Circulator Boot may both decrease edema and increase leg perfusion.
  
  
• Kakkos SK, Griffin M, Geroulakos G, Nicolaides AN: The efficacy of a new portable sequential compression device (SCD Express) in preventing venous stasis. J Vasc Surg 42:296-303, 2005. Abstract: OBJECTIVE: It has been previously shown that the SCD Response Compression System, by sensing the postcompression refill time of the lower limbs, delivers more compression cycles over time, resulting in as much as a 76% increase in the total volume of blood expelled per hour. Extended indications for pneumatic compression have necessitated the introduction of portable devices. The aim of our study was to test the hemodynamic effectiveness of a new portable sequential compression system (the SCD Express), which has the ability to detect the individual refill time of the two lower limbs separately. METHODS: This was an open, controlled trial with 30 normal volunteers. The new SCD Express was compared with the SCD Response Compression System in the supine and semirecumbent positions. The refilling time sensed by the device was compared with that determined from velocity recordings of the superficial femoral vein using duplex ultrasonography. Baseline and augmented flow velocity and volume flow, including the total volume of blood expelled per hour during compression with the SCD Express, were compared with those produced by the SCD Response compression system in the same volunteers and positions. RESULTS: Both devices significantly increased venous flow velocity as much as 2.26 times baseline in supine position and 2.67 times baseline in semirecumbent position (all P < .001). There was a linear relationship between duplex ultrasonography-derived refill time and the SCD Express-derived refill time in both the supine (r = 0.39, P = .03) and semirecumbent (r = 0.71, P < .001) positions but not with the SCD Response. Refill time measured by the SCD Express device was significantly shorter and the cycle rate higher in comparison with the SCD Response in both positions. The single-cycle flow velocity and volume flow parameters generated by the two devices were similar in both positions. However, median (interquartile range) total volume of blood expelled per hour was slightly higher with the SCD Express device in the supine position (7206 mL/h [range, 5042-8437] vs 6712 mL/h [4941-10,676]; P = .85) and semirecumbent position (4588 mL/h [range, 3721-6252] vs 4262 mL/h [3520-5831]; P = .22). Peak volume of blood expelled per hour by the SCD Express device in the semirecumbent position was significantly increased by 10% in comparison with the SCD Response (P = .03). CONCLUSIONS: Flow velocity and volume flow enhancement by the SCD Response and SCD Express were essentially similar. The latter, a portable device with optional battery power that detects the individual refill time of the lower limbs separately, is anticipated to be associated with improved overall compliance and therefore optimized thromboprophylaxis. Studies testing its potential for improved efficacy in preventing deep vein thrombosis are justified.
  
  
• Kakkos SK, Geroulakos G, Nicolaides AN: Improvement of the walking ability in intermittent claudication due to superficial femoral artery occlusion with supervised exercise and pneumatic foot and calf compression: a randomised controlled trial. Eur J Vasc Endovasc Surg 30:164-75, 2005. OBJECTIVES: To compare the effect of unsupervised exercise, supervised exercise and intermittent pneumatic foot and calf compression (IPC) on the claudication distance, lower limb arterial haemodynamics and quality of life of patients with intermittent claudication. METHODS: Thirty-four eligible patients with stable intermittent claudication were randomised to IPC (n = 13, 3h/d for 6 months), supervised exercise (n = 12, three hourly sessions/week for 6 months) or unsupervised exercise (n = 9). In each patient, initial claudication distance (ICD), absolute claudication distance (ACD), resting ankle brachial pressure index (ABPI), and resting hyperaemic calf arterial inflow were measured before, 6 weeks, 6 months and 1 year after randomisation. Quality of life was assessed with the short form (SF)-36, walking impairment (WIQ) and intermittent claudication questionnaires (ICQ). RESULTS: Compared with unsupervised exercise, both IPC and supervised exercise, increased ICD and ACD, up to 2.83 times. IPC increased arterial inflow (p < 0.05 at 6 weeks) and ABPI. Supervised exercise decreased arterial inflow and increased ABPI (p < 0.05 at 6 months). Unsupervised exercise had no effect on arterial inflow or ABPI. IPC improved significantly the ICQ score and the speed score of the WIQ, while supervised exercise improved the WIQ claudication severity score. At 1 year clinical effectiveness of supervised exercise and IPC was largely preserved. CONCLUSIONS: IPC, by augmenting leg perfusion, achieved improvement in walking distance comparable with supervised exercise. Long-term results in a larger number of patients will provide valuable information on the optimal treatment modality of intermittent claudication.Comments: This article is included not because it describes the use of equipment similar to the Circulator Boot, or because it describes impressive therapeutic results or because it deserves attention because of its size; it does not. Rather, it is included because the Aetna Insurance company quotes it as one of a few articles supporting pneumatic boot therapy in patients with arterial disease. Likely, Aetna was influenced by the title of the article which included the popular terms: "randomized" and "controlled". These patients were described as having claudication in association with disease of the superficial femornal artery. As with Ramaswami et al discussed below, the ArtAssist pneumatic device used inflated to 120 mmHg first a foot cuff and then a second later a calf cuff with a frequency of 3 compressions a minute. Of 151 patients screened for the study, 13 were allocated to the IPC treatments and 9 were available for analysis at six months. 117 were initially excluded to produce a study population with significant claudication free of other conditions (27 lines in their methods section) that might make the study difficult. In patients with calf arterial pressures less than 120 mm Hg, the device potentially blocks and even might reverse arterial inflow into the lower leg while successfully expelling venous blood. In patients in whom the arterial inflow was not reversed, emptying the veins increases the A/V pressure gradient when the pump was deflated. In contrast, Circulator Boot therapy in such patients would have delivered more compressions (either every beat or every other heartbeat), utilized a full leg bag thus treating the thigh also and provided concurrent therapy to the heart.
  
  
• Katz ES, Tunick PA and Kronzon I: Observations of coronary flow augmentation and balloon function during intraaortic balloon counterpulation using transesophageal echocardiography. Am J Cardiol 69: 1635-1639, 1992. ...&Quot; Noninvasively, transesophageal echocardiography"...(TEE)..." has demonstrated efficacy in enabling visualization of the proximal left coronary artery and in recording coronary blood flow velocity"... In 6 studied patients..."Peak diastolic coronary blood flow velocity increased by a mean of 117% (range 62 to 287) during balloon inflation (P=0.002). Furthermore, coronary flow velocity integral increased by a mean of 87% (range 43 to 176; P=0.003)." Balloon function and position also evaluated.
  
  
• Kavros SJ, Delis KT, Turner NS, Voll AE, Liedl DA, Gloviczki P, Rooke TW.: Improving limb salvage in critical ischemia with intermittent pneumatic compression: a controlled study with 18-month follow-up. J Vasc Surg 47(3):543-9,2008. BACKGROUND: Intermittent pneumatic compression (IPC) is an effective method of leg inflow enhancement and amelioration of claudication in patients with peripheral arterial disease. This study evaluated the clinical efficacy of IPC in patients with chronic critical limb ischemia, tissue loss, and nonhealing wounds of the foot after limited foot surgery (toe or transmetatarsal amputation) on whom additional arterial revascularization had been exhausted. METHODS: Performed in a community and multidisciplinary health care clinic (1998 through 2004), this retrospective study comprises 2 groups. Group 1 (IPC group) consisted of 24 consecutive patients, median age 70 years (interquartile range [IQR], 68.7-71.3) years, who received IPC for tissue loss and nonhealing amputation wounds of the foot attributable to critical limb ischemia in addition to wound care. Group 2 (control group) consisted of 24 consecutive patients, median age 69 years (IQR, 65.7-70.3 years), who received wound care for tissue loss and nonhealing amputation wounds of the foot due to critical limb ischemia, without use of IPC. Stringent exclusion criteria applied. Group allocation of patients depended solely on their willingness to undergo IPC therapy. Vascular assessment included determination of the resting ankle-brachial pressure index, transcutaneous oximetry (TcPO(2)), duplex graft surveillance, and foot radiography. Outcome was considered favorable if complete healing and limb salvage occurred, and adverse if the patient had to undergo a below knee amputation subsequent to failure of wound healing. Follow-up was 18 months. Wound care consisted of weekly débridement and biologic dressings. IPC was delivered at an inflation pressure of 85 to 95 mm Hg, applied for 2 seconds with rapid rise (0.2 seconds), 3 cycles per minute; three 2-hourly sessions per day were requested. Compliance was closely monitored. RESULTS: Baseline differences in demography, cardiovascular risk factors (diabetes mellitus, smoking, hypertension, dyslipidemia, renal impairment), and severity of peripheral arterial disease (ankle-brachial indices, TcPO(2), prior arterial reconstruction) were not significant. The types of local foot amputation that occurred in the two groups were not significantly different. In the control group, foot wounds failed to heal in 20 patients (83%) and they underwent a below knee amputation; the remaining four (17%, 95% confidence interval [CI], 0.59%-32.7%) had complete healing and limb salvage. In the IPC group, 14 patients (58%, 95% CI, 37.1%-79.6%) had complete foot wound healing and limb salvage, and 10 (42%) underwent below knee amputation for nonhealing foot wounds. Wound healing and limb salvage were significantly better in the IPC group (P < .01, chi(2)). Compared with the IPC group, the odds ratio of limb loss in the control group was 7.0. On study completion, TcPO(2) on sitting was higher in the IPC group than in the control group (P = .0038). CONCLUSION: IPC used as an adjunct to wound care in patients with chronic critical limb ischemia and nonhealing amputation wounds/tissue loss improves the likelihood of wound healing and limb salvage when established treatment alternatives in current practice are lacking. This controlled study adds to the momentum of IPC clinical efficacy in critical limb ischemia set by previously published case series, compelling the pursuit of large scale multicentric level 1 studies to substantiate its actual clinical role, relative indications, and to enhance our insight into the pertinent physiologic mechanisms.
  
  
• Keith SL, McLaughlin DJ, Anderson FA Jr, Cardullo PA, Jones CE, Rohrer MJ, Cutler BS: Do graduated compression stockings and pneumatic boots have an additive effect on the peak velocity of venous blood flow? Arch Surg 127(6):727-30, 1992. Graduated compression stockings and intermittent pneumatic compression boots reduce the incidence of deep vein thrombosis. Recent studies suggest that the simultaneous use of these devices may have a synergistic prophylactic effect; however, conflicting reports also exist. Using duplex imaging, we analyzed the effect on peak venous velocity in the superficial femoral vein produced by the individual and simultaneous use of graduated compression stockings and intermittent pneumatic compression boots. Normal volunteers and postoperative patients were examined. The use of intermittent pneumatic compression boots significantly increased the peak venous velocity relative to rest, whereas the use of graduated compression stockings did not alter the peak venous velocity. Also, the addition of graduated compression stockings to legs already being treated with intermittent pneumatic compression boots did not produce a further augmentation of peak venous velocity. This study demonstrates that the simultaneous use of graduated compression stockings and intermittent pneumatic compression boots does not produce a synergistic augmentation of peak venous velocity in the superficial femoral vein.
  
  
• Kern MJ, Henry RH, Lembo N, Park RC, Lujan MS, Ferry D and O'Rourke RA: Effects of pulsed external augmentation of diastolic pressure on coronary and systemic hemodynamics in patients with coronary artery disease. Am Heart J 110:727-735, 1985. Fourteen men with coronary heart disease and normal left ventricular function were studied. Peak diastolic blood pressure was augmented to within 5mm Hg of systolic pressure. External counterpulsation increased mean arterial pressure from 108±11 to 114±12 mm Hg (P<0.01) and the diastolic-pressure time index from 440±51 to 498±82 units (P><0.01) with no change in the systolic-pressure time index, absolute coronary sinus or great vein cardiac vein blood flow. External diastolic pressure augmentation did not affect heart rate, right heart hemodynamics, cardiac output, or calculated oxygen oxygen consumption. An unanticipated finding was a greater than or equal to 10% reduction in peak systolic pressure during external diastolic pressure augmentation in 8 of the 14 patients. The increase in the diastolic pressure-time/systolic pressure-time index suggests that subendocardial perfusion may be favorably influenced by diastolic pressure augmentation. Their leg pressure was applied 240 msec after the Q-wave of the EKG and was applied for 340 msec. Doppler studies showed a reversal of flow in the femoral artery.Comments: This is not end-diastolic pumping. For a patient with a pulse rate of 80 for example, the R-R interval would be 750 msec and their leg compression would end 170 msec before the next QRS complex.
  
  
• Knight MTN and Dawson K: Effect of intermittent compression of the arms on deep vein thrombosis in the legs. Lancet 2: 1265, 1976. Arm pumping decreased euglobulin lysis time and was associated with a decrease in leg thrombi.
  
  
• Koch CA: External leg compression in the treatment of vascular disease.Angiology 48, Number 5, Part 2: S3-S15, 1997. Author's summary: In summary, external compression of the limbs is a mode of therapy which has enjoyed a long history in the treatment of venous and arterial disease. Evidence suggests that its beneficial effects are mediated through enhancement of venous and arterial blood flow, promotion of vasodilatation, enhancement of fibrinolysis and, in the case of obstructive arterial disease, promotion of the development of collateral circulation. The utility of external leg compression in the prevention of deep venous thrombosis and in the management of chronic venous stasis disease has been well documented, and it has become an accepted treatment for these disorders. The use of pneumatic compression in the treatment of atherosclerotic peripheral vascular and cardiovascular disease is less widespread and their indications less well defined, though the work of a few investigators in each of these areas show striking benefits of the technique. Further investigation in these areas is warranted. Potential benefits to patients of external limb compression therapy include its noninvasive nature, its ability to be applied in the outpatient setting, and long-term cost savings through possible avoidance of hospitalization and invasive procedures. Comments: The author takes us back to Sir James Murray in 1812 and follows the development of boot therapy over the next 183 years. She is referring to intermittent pneumatic compression boots... not constant pressure stockings or wrappings.
  
  
• Kumbasar SD, Semiz E, Sancaktar O, Yalcinkaya S, Ermis C and Deger N: Concomitant use of intraaortic balloon counterpulsation and streptokinase in acute anterior myocardial infarction. Angiology 50: 465-471, 1999. Authors' summary: Using a prospective, nonrandomized design, the authors sought to determine whether concomitant use of intraaortic balloon counterpulsation (IABP) and streptokinase in acute anterior myocardial infarction (MI) would improve the in-hospital mortality rate and angiographic findings. The study included 45 patients with an acute anterior MI. All patients received intravenous streptokinase. Among these, 25 had concomitant IABP while the remaining 20 had streptokinase alone. All patients underwent cardiac catheterization. Patients treated with IABP had a significantly higher frequency of thrombolysis in myocardial infarction (TIMI) grade 3 flow (n: 11; 44% vs n:1 5%, p<0.05), and there was a trend toward a lower in-hospital mortality rate in the IABP group (n: 0; 0% vs N:3; 15%, p=0.08). The angiographic presence of thrombus image and grade >/= 2 coronary collateral circulation to the infarct-related coronary artery for the IABP and non-IABP groups did not differ significantly. The preliminary results of this study suggest that concomitant use of IABP and streptokinase in acute anterior MI increases the incidence of TIMI grade 3 flow and may have decreased the in-hospital mortality rate without unacceptable rates of vascular or hemorrhagic complications. Comments: Complications of their IABP included bleeding and groin hematomas requiring less than 3 units of blood transfusion in 4 patients, balloon rupture in one patient (another inserted without difficulty) and lower extremity ischemia resolving after removal of the balloon in 2 patients. External counterpulsation, of course, has no complications and can be applied more quickly. See Dillon (1998) above more more discussion on IABP vs external counterpulsation. This article by Kumbasar et al is included hopefully to encourage a similar study with the use of the Circulator Boot.
  
  
• Labropoulos N, Watson WC, Mansour MA, Kang SS, Littooy FN, Baker WH: Acute effects of intermittent compression on popliteal artery blood flow. Arch Surg 133:1072-5, 1998. Objectives: To investigate the immediate effects of intermittent pneumatic foot and calf compression (IPFCC) on popliteal artery blood flow in symptom-free volunteers and to determine the reproducibility of color flow duplex imaging in the popliteal artery. Results: Including all types of variability, the popliteal artery blood flow varied from 8% to 39% with a mean value of 19%. Since the diameter of the artery was obtained with less than 5% variability, the time average mean velocity was responsible for the high variation in flow. During application of the IPFCC, the popliteal artery blood flow increased significantly in all subjects (P<0.001). The mean increase in flow was 2.4 times baseline values. The diameter of the arteries remained unchanged while the time average velocity increased significantly (P><0.001). This velocity increase was due to marked elevation in the peak systolic and end diastolic velocities and diminution of the reverse-flow component, as well as a prolongation of the forward flow during diastole. After cessation of the pump, flow returned to baseline levels (P=.41). Comments: The authors placed inflatable 22- and 12-cm neoprene cuffs on the dorsum of the foot and the muscle mass of the calf, respectively. Their pump inflated to 120 mm Hg for 3 seconds at 12-second intervals with the foot cuff preceding the calf cuff by 2 seconds. Such timing maximizes venous return with this equipment. This equipment differs from the Circulator Mini-Boot in that (1) it compresses the lower leg at a pressure well above systolic pressure in many ischemic legs; (2) its longer compressions [3 seconds Vs 0.34 seconds for the Mini-Boot] may effectively block arterial inflow during its compression phase; (3) it does not encompass the entire lower leg so that its compressions send a pulse wave both proximally and distally with the distal pulse wave potentially stretching or breaking venous valves; (4) it is not cardiosynchronous; (5) it does not lend itself well to the usage of local antibiotics and foot soaks; (6) the authors offer no data showing that its usage has favorably altered blood flow in ischemic legs.
  
  
• Labropoulos N.1; Wierks C.1; Suffoletto B.1: Intermittent pneumatic compression for the treatment of lower extremity arterial disease: a systematic review. Vascular Medicine 7: 141-148, 2002. Abstract: This study aimed to identify the role of intermittent pneumatic compression in treating peripheral arterial disease and to investigate the types of treatment programs that are most effective. Data was sourced from English-language articles which were identified by a computer search using MEDLINE from 1966 to 2001, followed by extensive bibliography review. Studies were included if they contained pertinent material involving a compression device and arterial flow dynamics in lower limbs. A total of 26 English-language studies were identified that met the inclusion criteria. The diverse patient criteria and methods used in the studies provided an opportunity to examine the effectiveness of each, but made it difficult to compare one study with another. To assist in focusing on overall trends in improvement, patient type and treatment type disparities must be identified. In conclusion, it is evident that an intermittent pneumatic compression program appears promising and may be used in patients with severe peripheral arterial disease who are not candidates for revascularization using surgery or percutaneous angioplasty. It is now the goal to establish randomized, prospective, controlled trials to clarify the most beneficial regimen for treating such disease.
  
  
• Labropoulos N, Leon LR, Bhatti A et al: Hemodynamic effects of intermittent pneumatic compression in patients with critical limb ischemia. J Vas Surg 42:710-6, 2005. BACKGROUND: Traditional teaching assumes that the distal arterial tree is maximally dilated in patients with critical limb ischemia (CLI). Endovascular or arterial bypass procedures are the commonly used interventions to increase distal perfusion. However, other forms of treatment such as spinal cord stimulation or intermittent pneumatic compression (IPC) have been shown to improve limb salvage rates. This prospective study was designed to determine if the use of IPC increases popliteal, gastrocnemial, collateral arterial, and skin blood flow in patients with CLI. METHODS: Twenty limbs with CLI in 20 patients (mean age, 74 years) were evaluated with duplex ultrasound scans and laser Doppler fluxmetry in the semi-erect position before, during, and after IPC. One pneumatic cuff was applied on the foot and the other on the calf. The maximum inflation pressure was 120 mm Hg and was applied for 3 seconds at three cycles per minute. All patients had at least two-level disease by arteriography. Fourteen limbs were characterized as inoperable, and six were considered marginal for reconstruction. Flow volumes were measured in the popliteal, medial gastrocnemial, and a genicular collateral artery. Skin blood flux was measured on the dorsum of the foot at the same time. RESULTS: Significant flow increase during the application of IPC was found in all three arteries (18/20 limbs) compared with baseline values (P < .02). The highest change was seen in the popliteal, followed by the gastrocnemial and the collateral artery. After the cessation of IPC, the flow returned to baseline. This was attributed to the elevation of time average velocity, as the diameter of the arteries remained unchanged. The skin blood flux increased significantly as well (P < .03). In the two limbs without an increase in the arterial or skin blood flow, significant popliteal vein reflux was found. Both limbs were amputated shortly after. CONCLUSIONS: IPC increases axial, muscular, collateral, and skin blood flow in patients with CLI and may be beneficial to those who are not candidates for revascularization. Patients with significant venous reflux may not benefit from IPC. This supports the theory that one of the mechanisms by which IPC enhances flow is by increasing the arteriovenous pressure gradient.Comments: These authors are using the same apparatus critiqued above. Here they give some vascular data. In their discussion, they include the long term success of Vella et al (below) inferring the success was obtained with the same IPC apparatus they utilized; not so... Vella et al reported on their usage of the Circulator Boot.
  
  
• Landis EM and Hitzrot LH: Treatment of peripheral vascular disease by means of suction pressure. Ann Intern Med 3:1, 1935.
  
  
• Landis EM: Results of treatment with the Landis Suction-Pressure Boot. The Metabolic Service of Edward Dillon. Philadelphia General Hospital. Penna Med J 38:579-583, 1935. Objects of treatment (usual treatment having failed): (1) to promote healing of trophic lesions and (2) to allay ischemic pain.
  

  Patient Category	Results
  Diabetes, arteriosclerosis	Good ........................................14
  chronic ulcer.............,....6	Ulcers healed....... 3
  superficial gangrene........4	gangrenous plaque sep- arated and healed..4
  pain...............................5	pain relieved ........ 7
  Thrombo-angitis obliterans...............3	Encouraging but incomplete..........1
  Arteriosclerosis with ulcer................2	Failure.........................................3 osteomyelitis present
  Average number of hours of treatment 21.5

  Comments: Not too bad for an era before antibiotics. They did better in situations not involving infection (pain relief) as opposed to ulcers and osteomyelitis. Edward Dillon was the father of Richard Dillon (born 1933), inventor of the Circulator Boot.
  
  
• Lawson WE, Hui JCK, Soroff HS, Zheng ZS, Kayden DS, Sasvary D, Atkins H and Cohn PF: Efficacy of enhanced external counterpulsation in treatment of angina pectoris. AM J Cardiol 70: 859-862, 1992. Eighteen patients with chronic angina despite medical and surgical RX treated 1 hour daily for 36 hours. All patients improved in symptoms and generally decreased their need for meds. 16 were completely relieved. Serial thallium stress testing showed complete resolution of ischemic defects in 12 patients (67%), reduction in area of ischemia in 2 (11%), and no change in 4 (22%). The exercise duration of max stress testing improved from 8.14+/-0.71 to 9.72+/-77 minutes (P <: 0.005) although the double product did not change significantly. Authors claim that EECP uses thigh balloons and sequenced balloon inflation thus improving their diastolic augmentation over previously available methods. Exclusion criteria included clinical CHF*, aortic insufficiency, recent myocardial infarction (last 3 months)* significant ventricular ectopy* or atrial fibrillation, nonischemic cardiomyopathy*, severe occlusive peripheral vascular disease*, recurrent deep vein thrombophlebitis*, systemic hypertension, and a bleeding diathesis. Comments: * Items have not been contraindications for therapy with the Circulator Boot.
  
  
• Lawson WE, Hui JC, Zheng ZS, Oster Z, Katz JP, Diggs P, Burger L, Cohn CD, Soroff HS and Cohn PF: Three-year sustained benefit from enhanced external counterpulsation in chronic angina pectoris. Am J Cardiology 75:840-841, 1995. Exclusion criteria similar to study above. Follow-up of 18 patients with positive thallium stress tests who were given 36 hours of EECP. Studied within a week after the treatment, 11 patients no longer had evidence of ischemia with the same cardiac workload, three had less ischemia and four were unchanged. Over the next three years, 8 patients received supplemental EECP. At the three yar follow-up, 8 of the 14 patients with initial improvement remained negative, one was lost to follow-up, one refused follow-up stress testing, two had reverted to positive tests, one had a myocardial infarction and one had a coronary bypass graft (CABG). Of the four with ischemia before and after their initial EECP, two had continued abnormal tests, one had PTCA and one had CABG. Comments: It is interesting to note the qualification about no ischemia at the same cardiac workload. We commonly find less angina in our patients treated with the Circulator Boot at the same walking distance.... but as their claudication improves, their walking distance and walking speed may increase still producing angina at the greater cardiac workload.
  
  
• Lawson WE, Hui JCK, Zheng ZS, Burger L, Jiang L, Lillis O, Soroff HS and Cohn PF: Can angiographic findings predict which coronary patients will benefit from enhanced external counterpulsation? Am J Cardiol 77:1107-1109, 1996. This study evaluated and appeared to confirm the hypothesis that a patent vascular conduit was necessary for the efficacy of this treatment via transmission of the augmented diastolic perfusion pressure to the distal coronary artery. The patients were given 35 hours of EECP treatment as five hours a week over seven weeks. Perfusion defects improved in 18 of 19 (95%) patients with 1-vessel disease, in 17 of 19 (90%) patients with 2-vessel disease and 5 of 12 (42%) with 3-vessel disease. EECP may offer promise in some patients in whom complete revascularization is not feasible; in such cases, palliative PTCA or CABG may decrease the coronary artery disease extent to residual 1- or 2- vessel disease that might benefit from counterpulsation.
  
  
• Lawson WE, Hui JCK, Zheng ZS, Burger L, Jiang L, Lillis O, Oster Z, Soroff H and Cohn PF: Improved exercise tolerance following enhanced external counterpulsation: cardiac or peripheral effect? Cardiology 87:271-275, 1996. Twenty-two of 27 (81%) patients treated with EECP improved their exercise tolerance and 21 of the 27 improved their radionuclide stress perfusion images. Post-EECP maximum exercise heart rate and blood pressure, while demonstrating a linear relation with exercise duration, did not increase significantly despite the increased exercise duration. This, the authors suggest, may mean that the increase in exercise duration after treatment was due to both an improved myocardial perfusion and altered exercise hemodynamics. EECP thus appears to exert a "training" effect, decreasing peripheral vascular resistance and heart rate response to exercise. Coronary disease patients may improve their exercise tolerance after EECP because of both improved myocardial perfusion and a decrease in cardiac work load. There were 26 men and one woman in the study. The patients received 35 hours of treatment (1-2 hours daily). The increase in exercise duration was highly significant but modest increasing from 7.17 ± 0.53 to 8.84 ± 0.50 minutes. The patients who had an improved perfusion image after treatment had higher exercise durations both before and after treatment than the group as a whole: 7.22 ±0.63 increasing to 9.12 ±0.60 minutes.
  
  
• Lawson WE, Hui JCK, Oster ZH, Zheng ZS, Cabahug C, Katz JP, Dervan JP, Burger L, Jiang L, Soroff HS, Cohn PF:Enhanced external counterpulsation as an adjunct to revascularization in unstable angina. Clin Cardiol 20, 178-180, 1997. Despite intensive risk factor modification, a patient required two surgical coronary revascularizations and seven multivessel angioplasties over a 26 month period, demonstrating recurrent unstable angina and persistent thallium perfusion defects despite revascularization. Post EECP, angina was relieved, thallium defects were resolved, and the patient remained asymptomatic for 36 months.
  
  
• Lawson WE, Hui JC et al; for the IEPR investigators: Effect of enhanced external counterpulsation on medically refractory angina patients with erectile dysfunction. Int J Clin Pract. 61:757-62, 2007. Patients with refractory angina often suffer from erectile dysfunction. Enhanced external counterpulsation (EECP) decreases symptoms of angina, and increases nitric oxide release. This study evaluated the effect of EECP on sexual function in men with severe angina. The International Index of Erectile Function (IIEF) was used to assess erectile function of severe angina patients enroled in the International EECP Patient Registry. Their symptom status, medication use, adverse clinical events and quality of life were also recorded before and after completing a course of EECP. A cohort of 120 men (mean age 65.0+/-9.7) was enroled. The men had severe coronary disease with 69% having a prior myocardial infarction, 90% prior coronary artery bypass graft or percutaneous coronary intervention, 49% with three vessel coronary artery disease, 86% were not candidates for further revascularisation, 71% hypertensive, 83% dyslipidaemia, 42% diabetes mellitus, 75% smoking and 68% using nitrates. Functional status was low with a mean Duke Activity Status Inventory score of 16.6+/-14.8. After 35 h of EECP anginal status improved in 89%, and functional status in 63%. A comparison of the IIEF scores pre- and post-EECP therapy demonstrated a significant improvement in erectile function from 10.0+/-1.0 to 11.8+/-1.0 (p=0.003), intercourse satisfaction (4.2+/-0.5 to 5.0+/-0.5, p=0.009) and overall satisfaction (4.7+/-0.3 to 5.3+/-0.3, p=0.001). However, there were no significant changes in orgasmic function (4.2+/-0.4 to 4.6+/-0.4, p=0.19) or sexual desire (5.3+/-0.2 to 5.5+/-0.2). The findings suggest that EECP therapy is associated with improvement in erectile function in men with refractory angina. Comments: Male patients treated with the Circulator Boot commented often enough about having a return of nocturnal spontaneous erections for us to start a study that included an extension of the boot to include the penis in the treatment program. Early results were promising but referrals for the study ceased with the introduction of Viagra.
  
  
• Lawson WE, Hui JCK et al: Predictors of Benefit in Angina Patients One Year after Completing Enhanced External Counterpulsation: Initial Responders to Treatment versus Nonresponders Cardiology 103:201-206, 2005. Abstract: Enhanced external counterpulsation (EECP) has been shown to reduce Canadian Cardiovascular Society angina class. This study examines the factors that affect the reduction at 1 year, especially in patients who do not demonstrate an initial response. The data of 2,007 consecutive patients enrolled in the International EECP Patient Registry were analyzed. After 36.6 ± 4.9 h of EECP, angina was reduced by at least one class in 82.7%. At 1 year, 35.4% of initial nonresponders and 70.6% of responders remained improved by at least one angina class and free of major adverse cardiovascular events. Multivariate predictors of 1-year benefit are initial response to treatment (odds ratio 4.5, 95% CI 3.5-5.8), baseline angina class compared with class IV (odds ratios: class I 2.1, CI 0.93-4.81; class II 0.62, CI 0.43-0.87; class III 0.80, CI 0.62-1.01) and no history of congestive heart failure (odds ratio 1.41, CI 1.14-1.74).
  
  
• Lawson WE, Solver MA, Hui JCK, Kennard ED, Kelsey SF for the IEPR investigators: Angina patients with diastolic versus systolic heart failure demonstrate comparable immediate and one-year benefit from enhanced external counterpulsation. Journal of Cardiac Failure 11:61-66, 2005. Abstract: Background: Enhanced external counterpulsation (EECP) is effective in treating angina in coronary artery disease patients. Whether EECP produces similar immediate and sustained benefits and freedom from adverse events (MACE) at 1 year in patients with severe systolic dysfunction versus diastolic dysfunction is unknown. Methods and results: Data of 746 angina patients with a history of heart failure enrolled in the International EECP Registry were divided into 2 groups: left ventricular ejection fraction (LVEF) =35% (S) and LVEF >35% (D). Mean LVEF was 51.0 ± 10.2% in diastolic dysfunction (n = 391) versus 26.3 ± 6.9% in systolic dysfunction (n = 355). At baseline, 92.0% of diastolic dysfunction and 90.9% of systolic had Canadian Cardiovascular Society Class III/IV angina with similar number of anginal episodes and nitroglycerin use. After 32 hours of EECP, angina was reduced by =1 class in 71.9% of diastolic versus 72.2% of systolic with similar decreases in anginal episodes and nitroglycerin use. At 1-year 78.1% of diastolic and 75.8% of systolic have less angina than pre-EECP. MACE at 1 year was also comparable (24.4 versus 23.8%). Conclusions: The benefits of EECP in heart failure patients were similar regardless of diastolic or systolic dysfunction. The improvement was sustained at 1 year with similar MACE.
  
  
• Lippmann HI, Fishman LM, Farrar RH, Bernstein RK and Zybvert PA: Edema control in the management of disabling chronic venous insufficiency. Arch Phys Med Rehabil 75:436-441, 1994. A 15-year retrospective study assessing the biomedical and socioeconomic rationale of edema control in disabling chronic venous insufficiency... 2317 patients... Unna boot used for ulcerations and compression hosiery used for prevention of ulcerations... Approximate overall healing rate 60.9%.... The Unna boot is relatively cheap but does require regular clinic visits for replacement.
  
  
• Liu K, Chen LE, Seaber AV, Urbaniak JR: Influences of inflation rate and duration on vasodilatory effect by intermittent pneumatic compression in distant skeletal muscle. J Orthop Res 17(3):415-20, 1999. Previous study has demonstrated that application of intermittent pneumatic compression on legs can cause vasodilation in distant skeletal muscle at the microcirculation level. This study evaluated the influence of inflation rate and peak-pressure duration on the vasodilatory effects of intermittent pneumatic compression. The cremaster muscles of 50 male rats were exposed and divided into five groups of 10 each. A specially designed intermittent pneumatic-compression device was applied in a medial-lateral fashion to both legs of all rats for 60 minutes, with an inflation rate and peak-pressure duration of 0.5 and 5 seconds, respectively, in group A, 5 and 0 seconds in group B, 5 and 5 seconds in group C, 10 and 0 seconds in group D, and 10 and 5 seconds in group E. Diameters of arterial segments were measured in vessels of three size categories (10-20, 21-40, and 41-70 microm) for 120 minutes. The results showed that the greatest increase in diameter was produced by intermittent pneumatic compression with the shortest inflation rate (0.5 seconds). A moderate increase resulted from compression with an inflation rate of 5 seconds, and no effective vasodilation occurred during compression with the longest inflation rate (10 seconds). When the groups with different inflation rates but the same peak-pressure duration were compared, there was a significant difference between any two groups among groups A, C, and E and between groups B and D. When the groups with different peak-pressure durations but the same inflation rate were compared, compression with a peak-pressure duration of 5 seconds caused a generally similar degree of diameter change as did compression without inflation at peak pressure. The findings suggest that inflation rate plays an important role in the modulation of distant microcirculation induced by intermittent pneumatic compression whereas peak-pressure duration does not significantly influence the vasodilatory effects of the compression. This may be due to the fact that rapid inflation produces a significant increase in shear stress on the vascular wall, which stimulates vascular endothelium to release nitric oxide, causing systemic vasodilation. Comments: The authors went on to show that the vasodilation could be completely blocked by an inhibitor of nitric oxide synthase, NG-monomethyl-L-arginine implying that the production of nitric oxide was involved in the positive influence of intermittent pneumatic compression on circulation (J Orthop Res 17:88-95, 1999 and J Appl Physiol 92(2):559-66, 2002). The Circulator Boot, of course, also applies pressure for a short duration, commonly 0.42 seconds. While pumping on one leg, we have been able to document improved flow in the opposite leg by various techniques. In our case #143 in our case history section, we used NMR spectroscopy. In another case, we noted 100% oxygen by mask significantly raised polarographic subcutaneous PO2 levels faster when the opposite leg was treated in the Circulator Boot. In case #182, we show how pulse volume curves on the arms change with pumping on the legs. Many things happen with Circulator Boot therapy making the mechanism why remote tissue arterial flow increases unclear: cardiac output increases and venous blood and lymph fluid are expressed from the legs increasing volume presumably elsewhere. In this paper, the generation of nitric oxide is implicated and the desirability of rapid pulsations in promoting the effect is seen.
  
  
• Loh PH, Louis AA, Windram J, Rigby AS, Cook J, Hurren S, Nikolay NP, Caplin J, Cleland JG: The immediate and long-term outcome of enhanced external counterpulsation in treatment of chronic stable refractory angina. J Intern Med 259:276-84. 2006. BACKGROUND: Treatment of angina recalcitrant to conventional pharmacological therapy and revascularization remains problematic. Safe, effective and affordable treatments with high patient acceptability are desirable. Enhanced external counterpulsation (EECP) may fulfil these criteria better than many other proposed interventions. OBJECTIVE: To examine the immediate and long-term effect of EECP in treatment of chronic stable refractory angina. DESIGN: Prospective observational study of consecutive patients treated with EECP and follow-up for 1 year. SETTING: Teaching hospital. MAIN OUTCOME MEASURES: Canadian Cardiovascular Society (CCS) angina grading, weekly angina frequency and glyceryl trinitrate (GTN) use. RESULTS: Sixty-one patients were treated with EECP and 58 completed a course of treatment. Further analysis is confined to those who completed EECP. About 52% of patients suffered from CCS III and IV angina prior to EECP. Immediately post-EECP, angina improved by at least one CCS class in 86% and by two classes in 59%. At 1-year follow-up, sustained improvement in CCS was observed in 78% of the patients. The median weekly angina frequency and GTN use were significantly reduced immediately after EECP [7 (4-14) vs. 1 (0-4) episodes per week and 7 (2-16) vs. 0 (0-2) times per week respectively, P < 0.0001; data in median (interquartile range)]. The reduction was sustained at 1-year follow-up. In 48 patients, their mean exercise time improved significantly after EECP [301 +/- 130 s vs. 379 +/- 147 s, P < 0.0001]. Major adverse treatment-related events were rare. CONCLUSION: This study shows that for patients who fail to respond to conventional measures, a high proportion gain symptomatic benefit from EECP.
  
  
• Makhoul RG, Cole CW and McCann RL:Vascular complications of the intra-aortic balloon pump: an analysis of 436 patients. The Amer Surgeon 59:564-568, 1993. Indications for balloon therapy: intraoperative pump failure (42%), unstable angina (24%), preoperative prophylaxis (22%), preoperative shock (9%) and postoperative support (3%). Vascular complications occurred in 46 patients (10.6%) with leg ischemia, the problem in 40 of the 46. Only the absence of pedal pulses on admission correlated with an increase in vascular complications. Comments: Therapy with the Circulator Boot has not been associated with any such complications and is more rapidly utilized. We have had no studies to evaluate is function in the above roles.
  
  
• Manchanda A and Soran O: Enhanced external counterpulsation and future directions: step beyond medical management for patients with angina and heart failure. J Am Coll Cardiol 50:1523-31, 2007. Between 25,000 and 75,000 new cases of angina refractory to maximal medical therapy and standard coronary revascularization procedures are diagnosed each year. In addition, heart failure also places an enormous burden on the U.S. health care system, with an estimated economic impact ranging from $20 billion to more than $50 billion per year. The technique of counterpulsation, studied for almost one-half century now, is considered a safe, highly beneficial, low-cost, noninvasive treatment for these angina patients, and now for heart failure patients as well. Recent evidence suggests that enhanced external counterpulsation (EECP) therapy may improve symptoms and decrease long-term morbidity via more than 1 mechanism, including improvement in endothelial function, promotion of collateralization, enhancement of ventricular function, improvement in oxygen consumption (VO2), regression of atherosclerosis, and peripheral training effects similar to exercise. Numerous clinical trials in the last 2 decades have shown EECP therapy to be safe and effective for patients with refractory angina with a clinical response rate averaging 70% to 80%, which is sustained up to 5 years. It is not only safe in patients with coexisting heart failure, but also is shown to improve quality of life and exercise capacity and to improve left ventricular function long-term. Interestingly, EECP therapy has been studied for various potential uses other than heart disease, such as restless leg syndrome, sudden deafness, hepatorenal syndrome, erectile dysfunction, and so on. This review summarizes the current evidence for its use in stable angina and heart failure and its future directions. Comments: The systemic effects of booting are frequently surprising. Our Circulator Boot patients have noted improvement in vision, erectile function and a general sense of well-being.
  
  
• McCulloch JM, Marler KC, Neal MB and Phifer TJ:Intermittent pneumatic compression improves venous ulcer healing. Advances in Wound Care 7:22-26, 1994. Abstract: The effects of intermittent pneumatic compression on the healing rates of ulcers in patients with chronic venous insufficiency were examined in a prospective, controlled study of 22 patients. Patients were randomly assigned to the experimental or the control group. Both groups received local wound care followed by application of an Unna boot. In addition, subjects in the experimental group received intermittent pneumatic compression (IPC) twice weekly for one hour each session. Healing rates were reported in square centimeters per day. Data analysis revealed a mean healing rate of 0.08 cm2 per day for control subjects and 0.15cm2 per day for experimental subjects. Statistical analysis demonstrated the healing rates of the two groups to be statistically different. The results appear to indicate that intermittent compression is beneficial in the management of venous insufficiency ulcers.Comments: Our bias, of course, is that intermittent compression is indicated in all patients with stasis ulcers. Clinicians should compare the effects of the various devices on the market. Note if they restore transcutaneous PO2 levels. Note what happens to the texture and the turgor of the pumped areas. Are they softened and reduced in size or are they left firm with water merely expelled?
  
  
• Michaels AD, Barseness GW, Soran O, Kelsey SF, Kennard ED, Hui JC. Lawson WE: Frequency and efficacy of repeat enhanced external counterpulsation for stable angina pectoris (from the International EECP Patient Registry). Am J Cardiol 95:394-7, 2005. Abstract: We assessed the frequency, efficacy, predictors, and long-term success of repeat enhanced external counterpulsation (EECP) therapy in relieving angina in a large cohort of patients who had chronic angina pectoris and had undergone a full course of EECP. Within 2 years of the initial course of EECP, the rate of repeat EECP was 18%, which occurred at a mean interval of 378 days after initial EECP. Of those who underwent repeat EECP, 70% had a decrease of >/=1 angina class at the end of repeat EECP with similar decreases in nitroglycerin use.
  
  
• Montori VM, Kavros SJ, Walsh EE, Rooke TW: Intermittent compression pump for nonhealing wounds in patients with limb ischemia. The Mayo Clinic experience (1998-2000). Int Angiol 21(4):360-6. 2002. BACKGROUND: The aim of this retrospective observational study was to review the use of an intermittent pneumatic compression device on nonhealing wounds in patients with critical limb ischemia at Mayo Clinic Rochester. METHODS: The setting was a community and referral multidisciplinary wound care clinic. The authors analysed 107 patients, median age 73, with critical limb ischemia and active ulcers started using a compression device between 1998 and 2000; 101 patients had lower extremity ulcers, and 25% had a history of amputation, and 64% had diabetes. Of all the wounds, 64% were multifactorial in etiology, and 60% had associated transcutaneous oxygen tension levels below 20 mmHg. Patients were typically asked to use the device at home on the affected limb(s) for 6 hours daily. The main outcome criterion was complete wound healing with limb preservation. RESULTS: The median follow-up after initiation of treatment was 6 months. Complete wound healing with limb preservation was achieved by 40% of patients with TcPO(2) levels below 20 mmHg; by 48% with osteomyelitis or active wound infection; by 46% with diabetes treated with insulin; and by 28% with a previous amputation. Half of all amputations occurred in patients with prior amputations. Seven patients discontinued the device because of pain experienced with its use. CONCLUSIONS: Patients with critical limb ischemia and nonhealing wounds at high risk of amputation can achieve complete wound healing and limb preservation by using an intermittent pneumatic compression device.
  
  
• Morgan RH, Carolan G, Psaila JV, Gardner AMN, Fox RH and Woodcock JP: Arterial flow enhancement by impulse compression. Vasc Surg 25: 8-15, 1991. Abstract: Preliminary observations of rapid relief of ischemic rest pain following application of a foot impulse compression device prompted this study to quantify its immediate effects. Blood flow was calculated by means of a duplex ultrasound imager interfaced with a Doppler spectrum analyzer. Twelve normal subjects and 10 patients with peripheral vascular disease (mean Doppler ankle/brachial systolic pressure index = 0.62 (range 0.33-0.74) were studied. Mean resting blood flow (SD) was not significantly different in the two groups: 55.6 24.0 in normal subjects and 48.3 29.8 in the arteriopaths (p=>0.1). During five minutes of pump application in a 45-degree foot-down position, mean popliteal blood flow increased 93% in the normal group (p < 0.0001) and 84% in peripheral vascular patients (p < 0.03); there was no change in the opposite limb. In 5 normal subjects a "placebo" device produced no significant change in flow (p > 0.1). In 4 patients with vascular disease lying supine, impulse pumping produced no significant change in flow (p > 0.1). It is suggested that the hyperemic effect may be explained by the liberation of endothelial-derived relaxing factor (EDRF), a powerful relaxant of vascular smooth muscle, produced in response to sudden pressure changes (hemodynamic shear-stress) within the venous system. Comments: This device "consisted of a small portable pump and air reservoir that vents rapidly and intermittently into a small pneumatic pad held around the foot by a slipper (or beneath a cast). Inflation time was < 0.4 seconds, inflation pressure was approximately 100 mm Hg with a three second duration; the cycle was 20 seconds." This device is truly a "Mini" device. The Mini-Boot of the Circulator Boot Systems, in contrast compresses the entire leg beneath the knee for 0.34 seconds commonly in end-diastole after every other heartbeat... thus, delivering considerably more energy over a much larger area.
  
  
• Niezgoda JA, McGuire M, Radke S, Reynolds G: Circulator Boot Therapy for Limb Salvage: The Milwaukee Experience – 300 Patients. SAWC 2011 Poster-Oral Abstract Presentation. ( SAWC 2011 Poster-Oral Abstract Presentation Submission. Abstract: Introduction: Peripheral arterial disease affects 12-20% of the U.S. population. Approximately 2% of these individuals have critical limb ischemia (CLI) and 25% of CLI patients will require major amputation within one year of diagnosis. Patients with CLI that develop forefoot gangrene are at highest risk for amputation despite successful revascularization, as there are limited options for treatment of small vessel disease. Method: One treatment modality that has been used successfully in this group of patients is circulator boot therapy (CBT). CBT utilizes end diastolic pneumatic compression to improve arterial circulation in the leg, reverse tissue hypoxia and enhance wound healing. We analyzed of our database of over 300 patients that were managed with CBT. Our finding and results are reported. Results: This is the largest single center reported series of patients treated with CBT. The majority of these patients presented with severe and end stage arterial vascular disease at significant risk for below knee (BKA) or above knee amputation (AKA). Limb salvage was defined as achieving complete healing, improvement or decrease in wound size sufficient to safely allow discontinuation of CBT, or single digit or distal partial foot amputation which allowed for nonprosthetic ambulation. Limb salvage was accomplished in over 70% of these patients. Conclusion: Management of patients with CLI and forefoot gangrene is challenging and the risk amputation is high. Utilization of CBT can provide excellent results and prevent limb loss in select patients.(Comments: This clinic has operated with two Circulator Miniboots (treating from the tibial tuberosity to the toes) and one "B" Long Boot (designed to treat the whole leg in patients 63-69 inches in height...shorter folks take the "A" boot and taller the "C" boot.)
  
  
• Parmley WW, Chatterjee K, Charuzi Y, and Swan HJC:Hemodynamic effects of noninvasive systolic unloading (nitroprusside) and diastolic augmentation (external counterpulsation) in patients with acute myocardial infarction. Am J Cardiology 33: 819, 1974. Cardiac index rose 17%, peak diastolic blood pressure rose 20mm Hg and mean diastolic blood pressure rose 7mm Hg after external counterpulsation. Changes in pulse rate, systemic vascular resistance, right atrial pressure and pulmonary wedge pressure were not significant. Stroke work index rose in the patients who had had myocardial infarctions but not in controls.
  
  
• Pfizenmaier DH 2nd, Kavros SJ, Liedl DA, Cooper LT: Use of intermittent pneumatic compression for treatment of upper extremity vascular ulcers. Angiology 56:417-22, 2005. Ischemic vascular ulcerations of the upper extremities are an uncommon and frequently painful condition most often associated with scleroderma and small vessel inflammatory diseases. Digital amputation has been advocated as primary therapy because of the poor outcome with medical care. Intermittent pneumatic compression (IPC) pump therapy can improve ulcer healing in lower extremity ischemic ulcerations; however, the value of this treatment in upper extremity ischemic ulcerations is not known. This observational pilot study consisted of a consecutive series of 26 patients with 27 upper extremity ischemic vascular ulcers seen at the Mayo Gonda Vascular Center from 1996 to 2003. Inclusion criteria were documented index of ulcer size and follow-up ulcer size and use of the IPC pump as adjunctive wound treatment. Twenty-six of 27 ulcers (96%) healed with the use of the IPC pump. Mean baseline ulcer size was 1.0 cm2 (SD=0.3 cm2) and scleroderma was the underlying disease in 65% (17/26) of cases. Laser Doppler blood flow in the affected digit was 7 flux units (normal greater than 100). The mean ulcer duration before IPC treatment was 31 weeks. The average pump use was 5 hours per day. The mean time to wound healing was 25 weeks. Twenty-five of 26 patients reported an improvement in wound pain with pump use. Intensive IPC pump use is feasible and associated with a high rate of healing in upper extremity ischemic ulcers. A prospective, randomized, sham-controlled study of IPC is needed to determine whether IPC treatment improves wound healing compared to standard medical care. Comments: The patients here should have been pleased with their success. Pumping an average of 5 hours a day, they earned it. The "A" Circulator Boot can also be used to treat upper arm ischemia and has especially found usage in the Bryn Mawr Clinic among diabetic dialysis patients with areas of necrosis in the fingers.
  
  
• Podrid PJ: Redefining the role of antiarrhythmic Drugs. New Engl J Med 340:1910, 1999. First paragraph: "The growing recognition of the potentially harmful effects of antiarrhythmic drugs and the subsequent proof from controlled trials that some of these drugs increase the risk of death in some patients have led to a decline in their use. This change in practice has been fueled by the widespread application of nonpharmacologic therapies, such as implantable defibrillators and radio-frequency catheter ablation, which have now become the dominant types of therapy for many patients with ventricular and supraventricular arrhythmias." Podrid then reviews two other articles in the same journal issue, one describing success with sotalol and the other with the short-acting drug ibutilide. He concludes pointing out that authors did not recommend the routine use of either sotalol or ibutilide, that the drugs should be used when nonpharmacologic methods fail, and that drug therapy is continuing to evolve.Comments: This article is included to take the opportunity to discuss rhythm disturbances and booting. The occurrence of rhythm disturbances in our boot population is common. Patients with advanced peripheral arteriosclerosis obliterans may be expected to have coronary heart disease predisposing them to arrhythmias. The computer in the Circulator Boot monitor attempts to adjust boot decompression to maximize cardiac output in patients with atrial fibrillation (see Dillon, Angiology 1996 above). Still, if the heart is irregular, so are boot compressions and such irregularity is disturbing to both the patient and lay observers. Setting the boot to pump on alternate beats tends to decrease the irregularity. The 2:1 setting becomes a necessity if the heart rate is rapid (over 120); with irregular rates between 90 to 120, the 2:1 setting is desirable. Commonly, we attempt to slow rapid atrial fibrillation with either or both digoxin and a beta-blocker to rates below 80. We have been pleased to find that a modest number of patients may convert to normal sinus rhythm during their boot therapy. It is possible that the improved hemodynamics described above (Dillon, Angiology 1998) play a role. Another opportunity for a study?
  
  
• Rajarama S-S, Shanahanb J, Ashe C, Waltersc AS: Enhanced external counter pulsation (EECP) as a novel treatment for restless legs syndrome (RLS): a preliminary test of the vascular neurologic hypothesis for RLS. Sleep Medicine 6:101-106, 2005. Abstract: Background and purpose: Enhanced external counter pulsation (EECP) is used to treat angina. With sustained treatment this increases collateral circulation to the coronary arteries as well as to the body as a whole. We found some patients who underwent EECP for angina or congestive heart failure who also coincidentally had severe Restless Legs Syndrome (RLS). Case reports are presented. Patients and methods: Six patients with RLS (1F, 5M, ages 55–80) underwent EECP treatment. All patients were given the International RLS Study Group rating scale for RLS (the IRLS) before and immediately after 35 days of EECP treatment. Results: The average IRLS rating scale score of the six patients before treatment was 28.8 (range 23–35), which indicates frequent and moderate to very severe RLS. After 35 days of EECP treatment the IRLS score was 6 (P<0.03), which indicates clinically insignificant RLS. Long-term follow-up in three patients indicates sustained improvement in all three at 3–6 months after EECP was completed (IRLS score 28.3–3.33). Further follow-up in four patients showed sustained improvement in two patients 1 year after EECP was completed. Conclusion: EECP improves RLS symptoms significantly and could be considered as an adjunct treatment for patients with RLS. In some cases, the improvement lasts for months after the course of treatment. In this way EECP is unique and unlike pharmacotherapy which requires continuous daily treatment. Furthermore, our results suggest that decreases in vascular flow influence the peripheral or central nervous system leading to the sensory symptoms of RLS. A larger number of patients studied under blinded conditions is needed to draw further conclusions. Comments: The few patients we have seen with RLS have likewise been benefited with Circulator Boot therapy.
  
  
• Ramaswami G, D'Ayala M, Hollier LH et al: Rapid foot and calf compression increases walking distance in patients with intermittent claudication: results of a randomized study. J Vasc Surg 41:794-801, 2005. OBJECTIVE: The aim of our pilot study was to determine the usefulness of rapid, high-pressure, intermittent pneumatic calf and foot compression (IPCFC) in patients with stable intermittent claudication, with reference to the end points of improvement in initial claudication distance (ICD) (distance at which patient feels pain or discomfort in the legs), and improvement in absolute claudication distance (ACD) (distance at which patient stops walking because the pain or discomfort becomes severe). METHODS: Thirty male patients presenting with stable, intermittent claudication (ACD between 50 and 150 meters on treadmill testing at 3.8 km/h, 10 degrees gradient) were recruited into this pilot study from a single center. Fifteen patients were randomized to treatment with IPCFC (applied for 1 hour twice daily in the sitting position) and were also advised to have daily exercise, and 15 patients served as controls, who were advised exercise alone. All patients received aspirin and had resting and postexercise ankle/brachial index (ABI) measured at enrollment along with ICD and ACD on treadmill testing (3.8 km/h, 10 degrees gradient). The mean age, baseline ICD, and ACD of the treatment and control groups were 70.4 +/- 7 years and 70.7 +/- 9 years, 55.8 +/- 15 meters and 68.4 +/- 17 meters, and 86.7 +/- 19 meters and 103.9 +/- 27 meters, respectively. Both groups were equally matched for risk factors, including smoking, type II diabetes mellitus, and hypercholesterolemia. IPCFC was applied. The study protocol included follow-up visits at 1, 2, 3, 4, 6, and 12 months with the ABI, ICD and ACD being measured at every visit. RESULTS: The percent change from baseline for ICD and ACD for each patient visit and the mean +/- standard deviation (SD), standard error (SE), and median were calculated for the control and treatment groups. The percent change from baseline measurements (mean +/- SD) for ICD and ACD in the control group at 4, 6, and 12 months were 2.2 +/- 18 and 2.3 +/- 18, 2.9 +/- 17 and 5.2 +/- 20, and 3.6 +/- 18 and 5.8 +/- 20, respectively. In contrast, the changes in ICD and ACD at 4, 6, and 12 months in the treatment group were 137.1 +/- 128 (P < .01) and 84.3 +/- 82 (P < .01), 140.6 +/- 127 (P < .01) and 96.4 +/- 106 (P = .01), and 150.8 +/- 124 (P <0.01) and 101.2 +/- 104 (P <0.01), respectively. Although the ABI showed a slight increase in the treatment group, these differences were not statistically significant. CONCLUSIONS: The results of this pilot study show that IPCFC improves walking distance in patients with stable intermittent claudication. A significant increase in ICD and ACD was seen at 4 and 6 months of treatment, respectively, and the improvement was sustained at 1 year. The combination of IPCFC with other treatment such as risk-factor modification and daily exercise may prove useful in patients with peripheral arterial occlusive disease. It may be a useful first line of therapy in patients with disabling claudication who are unfit for major reconstructive surgery. Improved walking on long-term follow-up and experience from different centers may establish a role for this treatment modality in the future. Comments: This study is included not because of its size (15 patients in the treatment and control groups) or the success of follow-up (6 treatment and 5 control at one year), rather, it is included because the Aetna Insurance company quotes it as one of a few studies supporting the effectiveness of intermittent compression therapy in the treatment of arterial disease. The treatment group had an average of 140% improvement over their baseline walking distances while the control group changed little. The treatment group was asked to pump two hours a day in the ArtAssist equipment for over six months. The latter inflated around the foot and calf rapidly to 120 mm Hg three times a minute holding the pressure for three seconds each compression or 9 seconds a minute. One must be careful with such an apparatus in patients with advanced ischemia as shown by a reactive hyperemia test requiring one to three minutes before the return of the distal arterial pulses. In such patients, the 120 mm Hg inflation pressure may be sufficient to expel both the arterial and venous columns of blood from the leg and the interval between compressions may not be sufficient to allow the arterial column to be re-established. The Circulator Boot differs, of course, in providing more compressions, in not expelling the arterial column (the bag is placed to include a well-vascularized portion of the leg), in not impeding arterial inflow during systole and in providing concurrent cardiac support. The authors point out that the rapid inflation of their boots may have stimulated the endothelium to generate nitric oxide and prostacyclin. Such factors likely have more local than systemic effects and in their patients would be expected to have effects especially in the calf and foot. In contrast, the Long Circulator Boot would be expected to generate these factors throughout the leg and would further benefit patients with occlusive disease above the knee.
  
  
• Shea ML, Conti CR, Arora RR: An update on ennhanced external counterpulsation. Abstract: The development of advanced revascularization techniques has resulted in the growth of a subset of patients with coronary artery disease who are nonrevascularizable and are considered to have refractory angina. Enhanced external counterpulsation (EECP) has been developed for the management of these patients with chronic, refractory disease. Evidence has shown that through improvement of vascular endothelial function and recruitment of collateral vessels, EECP provides many clinical benefits. These patients experience sustained decreases in angina, improvement in exercise time, improved myocardial perfusion, and enhanced quality of life. Furthermore, EECP appears to be safe and effective in the treatment of angina in patients with impaired systolic function and has similar potential in patients with congestive heart failure. Comments: Those of us with experience with the Circulator Boot say amen.
  
  
• Shechter M, Matetzky S, Feinberg MS et al: External counterpulsation therapy improves endothelial function in patients with refractory angina pectoris. J Am Coll Cardiol 42:2096-8, 2003. OBJECTIVES: The goal of this study was to investigate the influence of short-term external counterpulsation (ECP) therapy on flow-mediated dilation (FMD) in patients with coronary artery disease (CAD). BACKGROUND: In patients with CAD, the vascular endothelium is usually impaired and modification or reversal of endothelial dysfunction may significantly enhance treatment. Although ECP therapy reduces angina and improves exercise tolerance in patients with CAD, its short-term effects on FMD in patients with refractory angina pectoris have not yet been described. METHODS: We prospectively assessed endothelial function in 20 consecutive CAD patients (15 males), mean age 68 +/- 11 years, with refractory angina pectoris (Canadian Cardiovascular Society [CCS] angina class III to IV), unsuitable for coronary revascularization, before and after ECP, and compared them with 20 age- and gender-matched controls. Endothelium-dependent brachial artery FMD and endothelium-independent nitroglycerin (NTG)-mediated vasodilation were assessed before and after ECP therapy, using high-resolution ultrasound. RESULTS: External counterpulsation therapy resulted in significant improvement in post-intervention FMD (8.2 +/- 2.1%, p = 0.01), compared with controls (3.1 +/- 2.2%, p = 0.78). There was no significant effect of treatment on NTG-induced vasodilation between ECP and controls (10.7 +/- 2.8% vs. 10.2 +/- 2.4%, p = 0.85). External counterpulsation significantly improved anginal symptoms assessed by reduction in mean sublingual daily nitrate consumption, compared with controls (4.2 +/- 2.7 nitrate tablets vs. 0.4 +/- 0.5 nitrate tablets, p <0.001 and 4.5 +/- 2.3 nitrate tablets vs. 4.4 +/- 2.6 nitrate tablets, p = 0.87, respectively) and in mean CCS angina class compared with controls (3.5 +/- 0.5 vs. 1.9 +/- 0.3, p <0.0001 and 3.3 +/- 0.6 vs. 3.5 +/- 0.5, p = 0.89, respectively). CONCLUSIONS: External counterpulsation significantly improved vascular endothelial function in CAD patients with refractory angina pectoris, thereby suggesting that improved anginal symptoms may be the result of such a mechanism.
  
  
• Schleicher SM and Milstein HJ: Treatment of pretibial mucinosis with gradient pneumatic compression. Arch Dermatol 130:842-844, 1994. Authors successfully treat an 83 year old man with multiple flesh-colored-to-erythematous indurated nodules and plaques over both anterior tibial areas. He also had non-pitting edema and a continuois drainage.
  
  
• Silverglade A: Peripheral vascular disease: diagnosis and treatment by passive vascular exercises. Arch Physical Therapy 21:100, 1940. Describes success with suction-pressure boot in the pre-antibiotic era.
  
  
• Smith PC, Sarin S, Hasty J and Scurr JH:Sequential gradient pneumatic compression enhances venous ulcer healing: A randomized trial. Surgery 108: 871-875, 1990. Abstract: The treatment of venous ulcers has remained largely unchanged for centuries. The application of properly applied graduated compression bandages, the use of graduated compression stockings, and surgery have been shown to achieve healing. However, some ulcers persist despite appropriate management. A randomized study was undertaken to compare two regimens of treatment for such patients. Both regimens included ulcer debridement, cleaning, nonadherent dressing, and graduated compression stockings. In one regimen, sequential gradient intermittent pneumatic compression was applied for 4 hours each day. Only one of 24 patients in the control group had complete healing of all ulcers compared with 10 of 21 patients healed in the intermittent pneumatic compression group. The median rate of ulcer healing in the control group was 2.1% area per week compared to 19.8% per week in the intermittent pneumatic compression group. The results indicate that sequential gradient compression is beneficial in the treatment of venous ulcers. Comments: Dillon (Angiology 1986) reported successful treatment with the Circulator Boot in 17 patients with refractory stasis ulcers. In his recent report on 2177 legs (Angiology 1997), there were 155 with difficult venous problems; 144 were healed or improved. Several had but a few treatments and were lost to followup. Many of these patients had tried other compression boots. The Circulator Boot, of course, delivers more energy to the leg than the usual sequential pneumatic boot; it compresses the leg forcefully after each heartbeat and tends to soften the leg.
  
  
• Solignac A, Ferguson RJ and Bourassa MG: External counterpulsation: coronary hemodynamics and use in treatment of patients with stable angina pectoris. Cath and Cardiovas Diag 3: 37-45, 1977. During ECP peak early and mean arterial and diastolic BP's significantly raised above control value by 32 and 14% respectively. But coronary sinus blood flow, LV O2 consumption, LV lactate extraction, mean systolic arterial BP, and cardiac index not significantly altered by ECP. Concluded ECP of doubtful value in Rx of patients with stable angina. Comment: Cardiassist apparatus (Medical Innovations Inc, Waltham, Mass) used. Leg pressures of 200-250 applied during the first two-thirds of diastole without attention paid to releasing the legs at a moment to maximize unloading of the left ventricle during systole. Indeed, their figure 1 shows presystolic brachial artery pressure to be higher during ECP than in the control period. While their peak diastolic blood pressure about matched systolic peak pressure, it was not in the very high range noted to be necessary in balloon angioplasty to dilate arteriosclerotic lesions.
  
  
• Soran O, Kennard ED, Kfoury AG, Kelsey SF, IEPR Investigators: Two-year clinical outcomes after enhanced external counterpulsation (EECP) therapy in patients with refractory angina pectoris and left ventricular dysfunction (report from The International EECP Patient Registry). Am J Cardiol 97(1): 17-20, 2006. Enhanced external counterpulsation (EECP) is a noninvasive circulatory assist device that has recently emerged as a treatment option for refractory angina in left ventricular (LV) dysfunction. This 2-year cohort study describes the long-term follow-up of patients who had severe LV dysfunction that was treated with EECP for angina pectoris and reports clinical outcomes, event-free survival rates, and the incidence of repeat EECP. This study included 363 patients who had refractory angina and LV ejection fraction < or =35%. Most patients reported quality of life as poor. After completion of treatment, there was a significant decrease in severity of angina class (p < 0.001), and 72% improved from severe angina to no angina or mild angina. Fifty-two percent of patients discontinued nitroglycerin use. Quality of life improved substantially. At 2 years this decrease in angina was maintained in 55% of patients. The 2-year survival rate was 83%, and the major adverse cardiovascular event-free survival rate was 70%. Forty-three percent had no reported cardiac hospitalization; 81% had no reported congestive heart failure events. Repeat EECP was performed in 20% of these patients. The only significant independent predictor of repeat EECP in a proportional hazard model was failure to complete the first EECP treatment course (hazard ratio 2.9, 95% confidence interval 1.7 to 4.9). Improvements in angina symptoms and quality of life were maintained at 2 years. In conclusion, for patients who have high-risk LV dysfunction, EECP offers an effective, durable therapeutic approach for refractory angina. Decreased angina and improvement in quality of life were maintained at 2 years, with modest repeat EECP and low major cardiovascular event rates.
  
  
• Soroff HS, Hui J and Giron, F.: Current status of external counterpulsation. Critical Care Clinics 2:277-295, 1986. Authors review history and various applications of ECP. Point out that the "Cardiassist" is the only apparatus used in the USA and that it provides external pressure over a limited portion of the thigh and leg..."in actual practice"..."over the lower third of the thigh". Conclude inclusion of the large upper thigh muscles crucial. Suggest that depressurization to atmosphere pressure as opposed to a negative pressure may be associated with a rise in systolic pressure possibly because of increased cardiac output and venous return. Various reports of ECP reviewed: Myocardial infarction, cardiogenic shock and angina. Except for the studies of Zheng below, most of these studies utilized courses of treatment of but a few hours. In summary, authors conclude improved treatments would include 1. treatment area to include the buttocks; 2. technique to include a negative pressure phase; 3. further investigation of graded sequential approach with negative phase; 4. treatment earlier in cardiogenic shock and for at lease 4 hours in cardiogenic shock. Comment: Circulator Boot therapy may include most of the thigh and is commonly done for many hours. Except for Dillon's (1998 above) small study on hemodynamics and RST changes on the Holter monitor, no formal studies have been organized for the use of the Circulator Boot in the treatment of cardiac disorders. Still, many of our leg patients have heart disease and in them we have had apparent success in individual patients with chronic congestive heart failure and angina. Further, we have seen pain relief in patients with an acute MI. Anecdotal measurements providing evidence for cardiac benefit have included: reduction of the loudness of mitral insufficiency murmurs; widening of the peripheral pulse tracing with leg pumping during systole; narrowing of the tracing with end-diastolic pumping; raising the dicrotic notch with systolic pumping and lowering it with end-diastolic pumping; and in patients with a Swann-Gans catheter in place, lowering wedge pressure and increasing cardiac output.
  
  
• Steinberg J: Cardiosynchronous limb compression: effects on noninvasive vascular tests and clinical course of the ischemic limb. Angiology 43:453-61, 1992. Abstract: Some patients with chronic arterial obstruction of the limbs may still suffer the consequences of advanced tissue ischemia, including ulceration and rest pain, and face threatened limb loss in spite of available surgical, pharmacologic, and other treatments. Additional therapeutic modalities were thus sought to accomplish limb salvage. A literature review indicated that most reports on R-wave-triggered circumferential limb compression (cardiosynchronous limb compression [CSC]) demonstrate its ability to augment limb arterial blood flow and improve ischemic limbs. To determine the device's efficacy and safety, and possibly confirm earlier positive reports, a systematic study was undertaken, using older, as well as newer, more electronically reliable CSC devices. The present study was designed to determine the following: 1. objectively, by noninvasive vascular tests, changes in limb blood flow, if any, by CSC; 2. clinical effects of CSC, if any, on the ischemic limb; 3. duration of CSC-induced limb improvements, if any; 4. side effects or safety of CSC. The study demonstrated that CSC treatments: 1. caused increased limb blood flow as determined by increased ankle/arm indices and hallux photoplethysmograph waveform amplitudes during treatments; 2. led, in most cases, to improvement in or resolution of the presenting ischemic problem (eg, ulcer, cellulitis, rest pain); 3. induced limb improvements that persist for up to seven years 4. caused no adverse side effects.
  
  
• Stevenson LW: Inotropic therapy for heart failure. N Engl J Med 339:1848-1850, 1998. In this editorial, Dr. Stevenson reviews the various inotropic agents (dopamine, dobutamine, pirbuterol, xamoterol, milrinone, pimobendan, flosequinan and, in the same issue of the New England Journal, vesarinone) and concludes all increase mortality rates versus placebo. Digoxin, she points out has a neutral effect on mortality. Current approved therapy, she concludes consists of diuretics and angiotensin-converting enzyme (ACE) inhibitors. Comment: Circulator Boot therapy has long been approved by the FDA in the treatment of patients with congestive heart failure. Dr. Dillon in unpublished data has noted what he calls the "marathon run effect". In explaining this effect, he suggests that the reader is running the Boston Marathon and keeping pace with a runner above his/her ability. The runners start up "heartbreak hill". The trained runner readily climbs the hill while the reader/runner becomes breathless and faint in the attempt to keep up. Would the breathless runner benefit from digoxin or dopamine? No, he/she would stop running and walk until he/she had recovered. Would the runner/reader then go home and quit the race. No, most likely he would resume the race and take more care with pace of running. What does the patient do when daily life becomes "heartbreak hill". Our patients "may walk" for forty minutes while they are in the Circulator Boot. After the treatment, they then "resume the race" and go home. Many of these patients can be kept compensated if they are booted 40 minutes three times a week. We are hoping others will avail themselves of this benefit of booting. Even more, we are hoping that some group will be interested in performing a clinical trial to document the benefit and its duration.
  
  
• Sultan S, Esan O, Fahy A: Nonoperative active management of critical limb ischemia: initial experience using a sequential compression biomechanical device for limb salvage. Vascular 16: 130-9, 2008. Critical limb ischemia (CLI) patients are at high risk of primary amputation. Using a sequential compression biomechanical device (SCBD) represents a nonoperative option in threatened limbs. We aimed to determine the outcome of using SCBD in amputation-bound nonreconstructable CLI patients regarding limb salvage and 90-day mortality. Thirty-five patients with 39 critically ischemic limbs (rest pain = 12, tissue loss = 27) presented over 24 months. Thirty patients had nonreconstructable arterial outflow vessels, and five were inoperable owing to severe comorbidity scores. All were Rutherford classification 4 or 5 with multilevel disease. All underwent a 12-week treatment protocol and received the best medical treatment. The mean follow-up was 10 months (SD +/- 6 months). There were four amputations, with an 18-month cumulative limb salvage rate of 88% (standard error [SE] +/- 7.62%). Ninety-day mortality was zero. Mean toe pressures increased from 38.2 to 67 mm Hg (SD +/- 33.7, 95% confidence interval [CI] 55-79). Popliteal artery flow velocity increased from 45 to 47.9 cm/s (95% CI 35.9-59.7). Cumulative survival at 12 months was 81.2% (SE +/- 11.1) for SCBD, compared with 69.2% in the control group (SE +/- 12.8%) (p = .4, hazards ratio = 0.58, 95% CI 0.15-2.32). The mean total cost of primary amputation per patient is euro29,815 ($44,000) in comparison with euro13,900 ($20,515) for SCBD patients. SCBD enhances limb salvage and reduces length of hospital stay, nonoperatively, in patients with nonreconstructable vessels.
  
  
• Topol EJ: Coronary-artery stents --- gauging, gorging and gouging. N Engl J Med 339:1702-1703, 1998. This editorial was written to accompany two other articles on stenting coronary arteries. The interested reader is encouraged to seek out the editorial itself. Here are some excerpts: ..."Coronary stenting is now the predominant form of nonsurgical myocardial revascularization and accounts for well over 60 percent of the percutaneous coronary revascularization procedures performed in the United States"... "The widespread use of stents by cardiologists predates the strong evidence provided by recent trials and probably reflects a response to angiographic gratification ( the x-ray image of a large, smooth arterial lumen ( which a colleague and I have called the 'oculostenotic reflex'. Cardiologists have mistakenly believed that stenting reduced the incidence of death and myocardial infarction. However, careful examination of the results of randomized trials comparing stenting with balloon angioplasty, including the trial by Erbel et al, shows an excess number of deaths and myocardial infarction among patients assigned to stents"...." To date, the only clinical benefit that has been shown for stenting, as compared with balloon angioplasty is a reduced need for target vessel revascularization."...."Unfortunately, in hospitals throughout the United States today, patients with lesions in small arteries, bifurcations, and extensive, diffuse atherosclerotic disease undergo stenting even though there are no data to support these applications". Comments: The cautious and critical elements of this editorial are included to provide those interested in using booting in the treatment of heart disease with information as to the limitations and hazards of various invasive techniques. Patients with peripheral arterial occlusive disease are almost certain to have coronary disease. We find that it is not uncommon for them, even though asymptomatic, to find their way to the invasive cardiologist who may perform an angioplasty with or without stenting. Quite commonly the balloon impacts plaque into the origin of a small artery producing a small infarct, which in the belief that a larger infarct may have been prevented by the procedure, is not reported to the patient. On occasion, the patient does not survive the procedure.
  
  
• Tschakovsky ME, Shoemaker JK, Hughson RL: Vasodilation and muscle pump contribution to immediate exercise hyperemia. Am J Physiol Heart Circ Physiol 271: H1697-H1701, 1996. Abstract: A rapid (within 0-5 s) increase in skeletal muscle blood flow has been demonstrated following muscle contraction, yet the mechanism remains unresolved. Recently, it was suggested that the entire rapid exercise hyperemia could be attributed to the mechanical muscle pump effect. Other evidence indicates that the muscle pump cannot increase arterial flow. We measured human forearm blood flow with the arm positioned above or below heart level during 1) simulation of rhythmic muscle pump function via repeated inflation/deflation of a forearm cuff to 100 mmHg to achieve mechanical emptying of forearm veins, and 2) 1-s single-cuff inflations, 1-s voluntary forearm contractions, and 1-s contractions performed within a cuff inflation. Rhythmic cuff inflation increased blood flow with the arm below heart level (P < 0.05) but not above. Flow following single contractions was higher than flow following cuff inflation within 2 s (P < 0.05). Peak flow increases due to a single mechanical venous emptying (7.7 +/- 0.7 ml.100 ml(-1) min(-1)) could account for 60% of the peak flow increase due to muscle contraction (12.8 +/- 1.0 ml.100 ml(-1).min(-1)) with the arm below heart level, whereas above heart level mechanical venous emptying accounted for 46% of the flow increase due to contraction (3.0 +/- 0.4 vs. 6.5 +/- 0.6 ml.100 ml(-1).min(-1)). We conclude that a functional muscle pump does exist in the human forearm in vivo, but that a rapid vasodilation detectable within 2 s also contributes to the early exercise hyperemia. Comments: We endeavor to have the leg/foot well below heart level in treating peripheral vascular insufficiency with the Circulator Boot. Conditions associated with swelling (venous stasis and lymphedema) on the other hand, may be treated in the supine position.
  
  
• van Bemmelen PS, Mattos MA, Faught WE, Mansour MA, Barkmeier LD, Hodgson KJ, Ramsey DE, Sumner DS: Augmentation of blood flow in limbs with occlusive arterial disease by intermittent calf compression. J Vasc Surg 19:1052-8, 1994. Authors' conclusions: An increased arteriovenous pressure gradient accounts for some but not all of the flow increase, much of which must be attributed to transient vasodilatation. Because the increase in flow does not depend on an increased inflow pressure and was not adversely affected by a low resting ankle-brachial pressure index or a low toe-pressure, intermittent external limb compression may deserve investigation as a possible adjunct to the nonoperative treatment of patients with severe arterial insufficiency. Comments: A transient benefit during a single treatment in this study. Patients with Circulator Boot treatments have long-lasting benefits after a series of treatments.
  
  
• van Bemmelen PS, Gitlitz DB et al: Limb salvage using high-pressure intermittent compression arterial assist device in cases unsuitable for surgical revascularization. Arch Surg 136:1280-5, 2001. HYPOTHESIS: Intermittent compression therapy for patients with inoperable chronic critical ischemia with rest pain or tissue loss may have beneficial clinical and hemodynamic effects. STUDY DESIGN: Case series of 14 consecutive ischemic legs that underwent application of a 3-month treatment protocol during a 2(1/2)-year study. SETTING: Veterans Administration Hospital. PATIENTS: Thirteen patients with 14 critically ischemic legs (rest pain, n = 14; tissue loss, n = 13) who were not candidates for surgical reconstruction were treated with rapid high-pressure intermittent compression. The patients had a mean age of 76.2 years, 8 were diabetic, and they represented 10% of referrals for chronic critical ischemia. They were not amenable to revascularization owing to lack of outflow arteries (n = 7), lack of autogenous vein (n = 5), or poor general medical condition (n = 3). INTERVENTION: All patients were instructed to use the arterial assist device for 4 hours a day at home for a 3-month period. MAIN OUTCOME MEASURES: Limb salvage and calibrated pulse volume amplitude. RESULTS: After 3 months, 9 legs had a significant increase in pulse-volume amplitude (P< .05). These legs were salvaged, whereas the 4 amputated legs demonstrated no hemodynamic improvement. We noted a direct correlation between patient compliance and clinical outcome. Patients in whom limb salvage was achieved used their compression device for longer periods of time (mean time, 2.38 hours a day) compared with those who underwent amputation (mean time, 1.14 hours a day) (P< .05). These mean hours of use were derived from an hour counter built into the compression units. CONCLUSIONS: Intermittent high-pressure compression may allow limb salvage in patients with limb-threatening ischemia who are not candidates for revascularization. Further studies are warranted to assess intermittent compression as an alternative to amputation in an increasingly older patient population. Comments: Of the 45 articles KCI has on their website on the benefits of the Artassist, this is the only one finding its way to publication that involves limb salvage. Most involve improvement in vascular tests or the benefits seen in claudication patients; several of these are included above.

  
  
  

• Vella A, Carlson LA, Blier B, Felty C, Kuiper JD and Rooke TW: Circulator boot therapy alters the natural history of ischemic limb ulceration. Vascular Medicine 5:21-25, 2000.(Mayo Clinic & Foundation, Rochester, MN) Abstract: Despite numerous advances in interventional radiology and vascular surgery, the clinician continues to be confronted with inoperable vascular disease. Previous studies have shown that ulceration associated with a transcutaneous oxygen pressure (tcPO2) of <20 mmHg is refractory to all attempts at healing. External pneumatic compression for the treatment of peripheral vascular disease has been available for several years, although there is a relative paucity of data regarding its role in clinical practice as well as its efficacy. The objective of this study was to examine the experience with circulator boot therapy in the treatment of ischemic ulcers in the absence of osteomyelitis, and specifically to determine whether such therapy can be of benefit in ischemic limb ulceration associated with a tcPO2 of ><20 mmHg. A retrospective chart review was undertaken of all patients with a lower limb ulcer who, in the absence of osteomyelitis, underwent circulator boot therapy at the Gonda Vascular Center. A total of 98 patients was identified. Two patients died within one month of commencing therapy and were not included in further analysis. The tcPO2 data were unavailable in five patients. Outcome in the patient population was classified as favorable if (1) healing was achieved, (2) the ulcer decreased in size, or (3) the affected limb improved sufficiently to allow successful revascularization. An unfavorable outcome was one where a major amputation was performed or where the ulcer increased in size. Out of a total of 29 patients with a tcPO2 <20 mmHG at the area of ulceration, 19 had a favorable outcome following circulator boot therapy. Of the remaining 62 patients with a tcPO2 >20 mmHG, 54 had a favorable outcome. Circulator boot therapy is associated with improved outcomes in limb ulceration due to peripheral vascular disease. Complete ulcer healing as well as preservation of the affected limb can be achieved in most cases. Comments: This study was accomplished at the Gonda Vascular Center at the Mayo Clinic. We are, of course, pleased with the favorable outcome of their study, but we had some misgivings when they undertook it. Mayo is a well known referral center that attracts patients from great distances. Many of these patients do not have the time or money to stay at Mayo many weeks and, as our case history section illustrates, difficult cases with advanced disease may require many weeks to be cured. It was quite possible that a study at Mayo might be negative because the patients were booted too briefly to have a clinical effect. Indeed, some of their patients were not healed at the time of discharge. In an attempt to further help these patients, they utilized non-cardiosynchronous home pump therapy in an identical percentage of patients in each of their outcome categories. They noted that in this study (which was not designed to study the effects of home therapy), this therapeutic modality did not seem to have additional benefits on the outcome of ischemic limb ulceration after Circulator Boot therapy.
  
  
• Vijavaraghavan K, Santora L, Kahn J et al: New graduated pressure regimen for external counterpulsation reduces mortality and improves outcomes in congestive heart failure: a report from the Cardiomedics External Counterpulsation Patient Registry. Congest Heart Fail 11:147-52, 2005. External counterpulsation (ECP) has been shown to increase exercise tolerance and reduce angina episodes, Canadian Cardiovascular Society Functional (CCSF) class, anginal medication usage, and hospitalizations in refractive CCSF class III and IV stable angina. However, the high pressures and resulting 1.5:1-2:1 peak diastolic to peak systolic pressure (D/S) ratios shown to be optimal in the treatment of angina can cause excessive preload and adverse effects in congestive heart failure (CHF) patients, particularly those with left ventricular ejection fractions <40%. Data were retrospectively analyzed from the Cardiomedics ECP Registry on 127 New York Heart Association (NYHA) class II-IV CHF patients (79.6% men; average age +/- SD, 68.2+/-15.6 years), with a comorbidity of CCSF class III-IV refractive angina, who were serially treated with 35 hours of ECP (1 h/d, 5 d/wk for 7 weeks) at unconventionally low pressures and D/S ratios under a new graduated pressure regimen. The pressures and D/S ratios were gradually increased in stages over the 7-week ECP regimen. The patients were divided into three groups based on the pressures applied and the resulting average D/S ratios (Low, Mid, and High). In the Low D/S ratio group (average D/S ratio 0.7:1), all-cause mortality in the year following ECP treatment was only 1.85% (one of 54 patients), whereas over the same time period in the Mid D/S ratio group (average D/S ratio 1.08:1), all-cause mortality was 7.69% (three of 39 patients) and in the High D/S ratio group (average D/S ratio 1.32:1), all-cause mortality was 8.82% (three of 34 patients). For the Low, Mid, and High D/S ratio groups, respectively: 1) average left ventricular ejection fractions increased 23.0%, 20.1%, and 17.5%; 2) NYHA class declined 36.6%, 29.6%, and 29.6%; and 3) all-cause hospitalizations, including terminal admissions, were reduced 85.7%, 82.6%, and 57.1% in the year following ECP therapy from the prior year. There were no adverse effects or withdrawals from the ECP therapy and no significant difference in sex-based outcomes. Consequently, ECP applied at low pressures and average D/S ratios of 0.7:1 under the new graduated pressure regimen is safe and effective in the treatment of CHF and produces a significant reduction in mortality, compared with the 8.5% annualized mortality of the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) (N=1232) of NYHA class II-III CHF and the 12.2% annual mortality of the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) study (N=595) of NYHA class III-IV CHF. Lower pressures improve patient comfort and may encourage more CHF patients to seek treatment. The reduction in hospitalizations should significantly reduce the cost of treating CHF. Comments: The ECP people are learning that the pressures utilized in the Circulator Boot are more effective than their previously used high pressures. Next, they need to learn about the advantages of end-diastolic pumping, avoiding pressure gradients up the leg, and anticipating the next heartbeat.
  
  
• Waggoner PC: Mechanical interventions after acute myocardial infarction: impact on patient outcome. Critical Care Nursing Clinical if N Am 4:359-363, 1992. Listed possible outcomes for patients with acute myocardial infarction: ISCHEMIC PHASE - prevent permanent myocardial necrosis, reduce myocardial oxygen consumption, restore adequate coronary artery circulation, relieve pain and discomfort and prevent dysrhythmias; INFARCT/NECROSIS PHASE - reduce infarct size, maintain adequate tissue perfusion, prevent complications, relieve pain and discomfort and prevent extension of infarction; and RECOVERY PHASE - promote maximum functional capacity, prevent further loss of functional myocardium and reduce risk factors. Criteria for total ventricular support: mean arterial pressure < 60 mm Hg; left atrial and/or right atrial pressure < 20 mm Hg, urine output < 20 ml/hr; cardiac index < 2L/min/M2 with: (a) maximum pharmacological therapy, (b) optimal preload (right atrial and left atrial pressures 15-20 mm Hg) and (c) intra-aortic balloon pump (if appropriate).
  
  
• Werbel GB and Shybut GT: Acute compartment syndrome caused by malfunctioning pneumatic-compression boot, a case report. J Bone and Joint Surgery 68-A:1445-1446, 1986. Jobst boot valve failed allowing leg compression at 40 mm Hg for 9 hours during surgery. Comments: Such an adverse outcome might be possible with the long Circulator Boot if (a) therapy was continued for many hours and (b) a fold of the plastic bag functioned as a flutter valve letting air into the boot but blocking its venting.
  
  
• Werner D, Hui JC, Kropp J, Daniel WG: Pneumatic external counterpulsation -- a therapy option in angina pectoris. Zeitschrift fur Kardiologie 87 suppl 2: 193-8, 1998. Abstract: Pneumatic external counterpulsation operates by applying ECG-triggered diastolic pressure via cuffs to the vascular bed of the lower limbs. Comparable with intra-aortic balloon pumping, PECP produces a diastolic augmentation combines with increase of mean arterial pressure and coronary perfusion. American, Asian, and our own data demonstrated a reduction of angina pectoris through repeated use of PECP one or two hours daily for four to seven weeks. Exercise testing and thallium scanning confirmed the clinical improvement. PECP is a virtually risk-free treatment option in patients suffering from angina despite medical and interventional treatment. Opening of collaterals and collateral growth induced by external counterpulsation are discussed as the cause of clinical benefit.
  
  
• Werner D, Michelson G et al: Changes in ocular blood flow velocities during external counterpulsation in healthy volunteers and patients with atherosclerosis. Graefes Arch Clin Exp Ophthalmol 239:599-602, 2001. BACKGROUND: External counterpulsation (ECP) is a new noninvasive means of augmenting organ perfusion by applying ECG-triggered diastolic pressure to the vascular bed of the lower limbs. In this study, effects of ECP on changes of ocular blood flow velocities were studied. METHOD: Mean, systolic and diastolic flow velocities of the ophthalmic artery were measured by Doppler sonography before and during ECP. Twelve healthy volunteers (age 31.3+/-4.3 years) and 12 patients with severe atherosclerosis (inclusion criteria: two atherosclerotic risk factors, at least one severe coronary stenosis, age 62.1+/-5.3 years) were included in the study. RESULTS: In healthy subjects, ECP changed diastolic flow velocity of the ophthalmic artery nonsignificantly from 21.6+/-7.7 to 23.7+/-10.5 cm/s. Systolic flow velocity decreased significantly from 36.1+/-13.6 to 28.9+/-10.2 cm/s (P<0.01). Mean flow velocity changed nonsignificantly from 28.1+/-9.4 to 26.5+/-9.9 cm/s. In atherosclerotic patients, mean flow velocity increased significantly from 26.3+/-11.4 to 29.3+/-11.2 cm/s (P<0.001), which was caused by significant diastolic flow augmentation from 19.7+/-9.1 to 23.9+/-9.7 cm/s (P<0.001). Systolic flow velocity was not changed significantly (from 34.2+/-12.8 to 32.6+/-11.8 cm/s). CONCLUSION: No significant change of mean blood flow velocity in the ophthalmic artery was found in young healthy subjects. In elderly patients with atherosclerosis, ECP significantly increased blood flow velocity in the ophthalmic artery by 11.4%. This may indicate an ocular perfusion benefit in these patients as a result of ECP and could also explain the increase of perfusion found in patients with retinal ischemia after ECP.
• Werner D, Michalk F, Hinz B, Werner U, Voigt JU, Daniel WG: Impact of enhanced external counterpulsation on peripheral circulation. Angiology 58: 185-190, 2007. Enhanced external counterpulsation (EECP) is a noninvasive counterpulsation technique that reduces angina and improves exercise capacity in patients with coronary artery disease. Diastolic coronary perfusion is augmented by pneumatic compression of 3 sets of cuffs wrapped around the lower extremities. Although central hemodynamic changes are well investigated, almost no data exist about the changes of peripheral circulation during EECP. In this study, 12 patients with angina and angiographic evidence of coronary artery disease were treated for 1 hour with EECP. In these patients, peripheral artery disease was excluded by duplex sonography. The patients rested 1 hour before EECP in supine position, and they remained in that position for 1 hour after the procedure. Changes of flow volumes and flow pattern of the posterior tibial artery and the brachial artery were measured by sonography at the end of all 3 periods. Furthermore, we measured the concentration of circulating prostanoids at these 3 time points. Averaged flow volume of the posterior tibial artery decreased to 69% +/- 23% (P < .05) during EECP and increased to 133% +/- 34% (P < .05) of baseline 1 hour after the procedure. In contrast, the averaged flow volume of the brachial artery increased by 9% +/- 4% (P < .05) during EECP and returned to baseline values after EECP. The flow pattern of the posterior tibial artery showed a second early diastolic antegrade flow caused by the cuff inflation and a reverse end-diastolic flow after the deflation of the cuffs. These flow changes caused an increase of the pulsatility index by Gosling (397% during EECP), returning to baseline values in the recovery period. Plasma concentrations of circulating prostanoids showed no significant change during EECP. Thus, pedal flow volume decreased to approximately two thirds of baseline during EECP followed by reactive hyperemia even 1 hour after the procedure; however, this decreased perfusion triggered no change of the prostacyclin/thromboxane ratio and was well tolerated by all investigated patients. The observed 4-fold increase of the peripheral pulsatility index supports the thesis of increase of shear-stress-related improvement of endothelial function during EECP. Comments: Here average flow decreased 69% during EECP and these patients were thought to have no peripheral vascular disease. Hui in his 2006 patent (US 7,048,702 B2 on ECP assigned to Vasomedical Inc) notes that a pressure drop of 10-30 mmHg is preferred between the various cuffs with pressures of 160 to 300 mmHg being applied to the distal cuffs and 160 to 250 being applied to the proximal cuffs to "milk" the peripheral blood back up the vascular tree. The standard reactive hyperemia vascular laboratory test reminds one how dangerous these pressures might be in patients with the peripheral vascular disease that commonly accompanies those with ASHD. In the test anoxia is produced by putting a tourniquet on the thigh for three minutes and then recording the time required for a Doppler pulse to return to the posterior tibial. In patients with advanced arteriosclerosis obliterans in whom the distal flow is derived through collaterals that first nourish the musculature before re-entering the tibial vessels, the time required may be a matter of minutes. In such patients significant leg ischemia may be anticipated throughout any ECP treatment.
  
  
• Werner D, Michalk F et al: Accelerated reperfusion of poorly perfused retinal areas in central retinal artery occlusion and branch retinal artery occlusion after a short treatment with enhanced external counterpulsation.. Retina 24:541-7, 2004.BACKGROUND: To date, no satisfactory therapy has become available for patients with acute central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO). Enhanced external counterpulsation (EECP) is a new noninvasive procedure that increases perfusion of inner organs. In the current study, the authors measured the impact of EECP on reperfusion in ischemic retinal tissue. METHODS: In a prospective, randomized study, 20 patients with CRAO or BRAO were included. Ten patients were given hemodilution therapy and 2 hours of EECP, and 10 patients were given regular hemodilution therapy only. Quantification of changes in retinal perfusion was carried out by means of scanning laser Doppler flowmetry (in arbitrary units). RESULTS: Enhanced external counterpulsation caused no observable adverse events. A significant increase in perfusion occurred immediately after EECP in the ischemic retinal areas (57 +/- 19 arbitrary units versus 99 +/- 14 arbitrary units). In contrast, no change was measured in the group not treated with EECP (83 +/- 19 arbitrary units versus 89 +/- 44 arbitrary units). Forty-eight hours later, a significant increase in perfusion could be shown in the ischemic retina of both groups, and no significant difference of perfusion was found between the two groups any longer. CONCLUSION: The current study suggests that EECP could be a clinically useful and safe procedure in patients with CRAO or BRAO to accelerate recovery of perfusion in ischemic retinal areas.
  
  
• Williams DO, Korr KS, Gewirtz H and Most AS:The effect of intraaortic balloon counterpulsation on regional myocardial blood flow and oxygen consumption in the presence of coronary artery stenosis in patients with unstable angina. Circulation 66: 593-597, 1982. Six patients studied. Counterpulsation treatment with the intraaortic ballon decreased the rate-pressure product and aortic-end diastolic pressure; and the peak systolic aortic pressure and regional myocardial oxygen consumption declined in 5 of the 6 patients. Peak and mean aortic diastolic blood pressures increased. Changes in regional coronary blood flow paralleled changes in peak systolic aortic presssure (P< 0.007). Thus, relief of angina during IABP could not be ascribed to an increase in regional coronary blood flow. Reduction of myocardial oxygen consumption was thought to be the most likely mechanism by which IAPB relieves myocardial ischemia in patients with unstable angina. Nine patients were actually studied but the thermodilution catheter could not be placed in two and one could not be satisfactorily pumped. The data on the remaining six patients comprise the report. Five of the 6 had an insignificant 5% fall in peak systolic pressure; the five also had a 56% rise in peak diastolic pressure, a 17% rise in mean diastolic pressure, a 21% fall in end-diastolic aortic pressure and a 14.1% drop in myocardial O2 consumption. In their discussion, the authors noted that coronary flow may go up in shock patients as it is diminished by the low aortic pressure. Comments: This article is included because it is commonly quoted in textbooks of cardiology and illustrates how thin the data is that points to a significant hemodynamic effect for the aortic balloon.
  
  
• Yu S, Da H and Zhen Z: External Counterpulsation, Review Article. Chinese Med J 103(9): 768-771, 1990. ECP available in 1800 medical units. A 3 stage sequential ECP controlled by a microprocessor. ANGINA PECTORIS: 1. Short term: symptoms in 52.6% of 3218 cases significantly improved, 30.3% improved, 8% no change and 0.2% deteriorated. In 5067 cases, the EKG had significant improvement in 20.5%, improved in 47.8%, did not change in 30.5% and deteriorated in 1.2%. 2. Long term results likewise were significantly better in ECP group versus a placebo medication group. MORTALITY in angina patients: ECP vs placebo in 1st and 8th years: 4.9 vs 13.51 (1st year) and 7.69 vs 30.3 (8th year). TREATMENT OF ISCHEMIC CEREBRAL DISEASES: in small series ECP more effective than medication. OTHER APPLICATIONS: Effective in 87.2% of cases of sudden deafness. Effective in treatment of thrombus of the retinal artery, traumatic optic atrophy, and serous central retinopathy. Comment: Effect of ECP largely attributed by author to rise in diastolic pressure presumably promoting collateral blood flow in various tissues. Similar successes have been seen in small numbers of patients treated with the Circulator Boot without the same amount of increase in diastolic pressure and have been attributed to other factors such as an increase in the level of circulating fibrinolysins.
  
  
• Zheng Z-s, Li T-m, Kambic H, Chen G-h, Yu L-q, Cai S-r, Zhan C-y, et al: Sequential external counterpulsation (SECP) in China. Trans Am Soc Artif Intern Organs 29: 599-603, 1983. Previous apparatuses which raise diastolic augmentation but 26-32% unsatisfactory while studies raising DA 59-104% effective. Here DA raised 43.9% higher than obtained with 4-limb SECP alone. Unique features of this apparatus: synchronized with heartbeat and follows pulse rate; a series of solenoids activated at 50 msec intervals; a screen displaying the ECG, the signals to the solenoid valves, and an earlobe plethysmography; a deflation of premature beats; balloon pressures of 265mm distally, 240 proximally, and 200 on the buttocks; and an exhaust system that empties "before the heart enters systole" to reduce afterload. 97% of 200 angina patients relieved with improved EKG in 63.8% and little relapse when Rx stopped (40 controls treated with Segontin had relief in 72.5% and improved EKG's in 40%, half relapsing after drug stopped). In 52 patients with an acute MI, 95.7% relieved of pain within a few hours and 5.8% dies vs mortality of 18.4% in 152 controls. When the effects of SECP were evaluated with the mapping method of Maroko et al, the ZST and NST indicators of infarct size were found to increase in the control group and decrease in the SECP group. Comment: This boot is used in supine position negating effect of gravity in reducing afterload.
  
  

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