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PubMed1979

[Use of the method of counterpulsation by means of an intra-aortic balloon in the treatment of myocardial infarct].

The results of applying counterpulsation with an intraaortic balloon in the treatment of 17 patients suffering from myocardial infarction are discussed. Counterpulsation was indicated in 15 patients because of cardiogenic shock and in 2 (with concomitant arterial hypertension) because of expansion of the zone of myocarial infarction against the background of unstable arterial pressure. Nine patients died, counterpulsation in these cases was begun 5 hours after the appearance of the shock symptoms or later. A comparative analysis of hemodynamic changes associated with counterpulsation in patients who survived and in those who died is made.

Adult↗

PubMed1983

Sequential external counterpulsation (SECP) in China.

A new SECP was developed and is currently successfully used in more than 120 clinics in China. This sequenced counterpulsation device has the effect of milking more blood as pressure is applied on the extremities in succession (first distally then proximally) and in decreasing values (265 to 200 mm Hg). In comparison of the 4 types of counterpulsation, namely nonsequenced leg and 4 limb counterpulsation, and sequenced 4 limb and 4 limb with buttock balloons, the SECP with buttock balloons method raised the DA to appreciably higher levels with respect to DA amplitude and area. DA was raised 43.9% higher than that obtained with 4 limb SECP alone. From our experimental and clinical results, we conclude that SECP with buttock balloons is a far more effective method providing greater diastolic augmentation than previously reported in the literature. Two hundred angina and 52 AMI patients who had undergone the SECP treatment constitute the basis of this report. The present work represents an analysis of 6 yrs experience with studies on the design, development and clinical evaluation of the SECP method. Ninety-seven percent of the angina patients obtained long-term symptomatic relief. Relapse was minimal. In 95.7% of the AMI patients chest pain or shock symptoms were rapidly relieved. SECP with high DA appears to be very effective in improving myocardial blood supply and ventricular function. Moreover, the simplicity and advantages of this noninvasive sequenced counterpulsation method have been reported (1063 cases) from 31 clinics in China. This method is convenient, safe, and far more effective than conventional drug therapy for patients with acute and chronic ischemic myocardial disease.

Angina Pectoris↗

PubMed1998

The efficacy of the high volume counterpulsation technique at very low levels of aortic pressure.

BACKGROUND: The objective of the present study was to identify the hemodynamic variables, that preclude the effectiveness of the counterpulsation technique. METHODS: In order to achieve high counterpulsation volume two devices were used simultaneously. The para-aortic counterpulsation device pumping 60-70 ml was implanted on the ascending aorta, and the intra-aortic balloon (20 ml) was placed in the descending aorta of 14 dogs with severe cardiogenic shock. Both devices were synchronized to provide aortic diastolic augmentation. The mechanical assistance provided by these devices was considered adequate when the mean aortic pressure during the supportive period was at least 50 mmHg, a pressure compatible with life. RESULTS: The mechanical assistance provided by the two devices was adequate in none (0%) of the cases with a systolic aortic pressure below 30 mmHg (Group I), in 71% of the cases with a systolic aortic pressure between 30-56 mmHg (Group II), and in 100% of the cases with a systolic aortic pressure above 56 mmHg (Group III). In group II the left ventricular end-diastolic pressure was higher in the cases responding adequately to mechanical assistance (Subgroup IIa) than in the ones where no adequate response was obtained (Subgroup IIb). CONCLUSIONS: The very low levels of the systolic aortic pressure was the most important factor precluding the adequate effectiveness of the counterpulsation technique.

Animals↗

PubMed2002

Impact of intra-aortic balloon counterpulsation with different balloon volumes on cardiac performance in humans.

Intra-aortic balloon (IAB) counterpulsation can augment the cardiac output. However, the effect of different IAB volumes on cardiac performance has not been adequately evaluated in humans. Eighty-two patients (52 males [63%]; mean age, 65 +/- 12 years; mean body surface area [BSA], 1.8 +/- 0.2 m(2)) had IAB counterpulsation for cardiogenic shock, refractory angina, and preoperatively for high-risk cardiac surgery. Cardiac hemodynamics were prospectively studied during IAB with inflation volumes of 32 vs. 40 cc. Hemodynamic data collected included aortic pressure, pulmonary artery pressure, systemic and mixed venous oxygen saturations, and cardiac output (by Fick). Transthoracic echocardiography (TTE) was used to obtain both velocity time integrals (VTIs) and the area of the left ventricular outflow tract (LVOT). Left ventricular stroke volume was then calculated as LVOT area x VTI. Cardiac output (CO) determined by the Fick method and VTI did not differ significantly (P = NS) between the two inflation volumes (y = 0.002 + 0.97x). In a subgroup of 33 patients with BSA <or= 1.8 m(2), the CO (by VTI) was slightly lower with IAB inflation volume of 32 vs. 40 cc (P = 0.05). Overall, smaller IAB inflation volumes do not affect the hemodynamic improvement seen during IAB counterpulsation. However, in patients with smaller BSA, larger inflation volumes may further augment CO.

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PubMed1992

Cardiovascular responses to external counterpulsation: a computer simulation.

A mathematical model of the human cardiovascular system is presented which includes a simulation of cardiac assistance by external counterpulsation. The model was established to study the effects of external counterpulsation on cardiovascular haemodynamics. The closed simulation includes both the left and the right heart and the pulmonary circulation. The model is able to provide data for the behaviour of the system under varying modes of assistance. Our results suggest that control of external counterpulsation is more difficult than control of the intra-aortic balloon pump and requires regulation of a larger number of variables. The results also suggest that a tradeoff exists between improved oxygen delivery to the heart and reduction in the oxygen consumption of the myocardium, an observation similar to that reported for the intra-aortic balloon pump.

Counterpulsation↗

PubMed2006

Mechanisms and evidence for the role of enhanced external counterpulsation in heart failure management.

Balloon counterpulsation has gained widespread acceptance as a therapy for cardiogenic shock. However, over the past four decades a parallel method of noninvasive counterpulsation, enhanced external counterpulsation (EECP), has been defined and developed. Mechanisms of benefit for this technology continue to emerge and include enhanced coronary and other key target organ perfusion beds. Other mechanisms include angiogenesis and enhanced cellular metabolism. Beyond putative mechanisms there is ample evidence for improved and sustained outcomes in patients with and without left ventricular dysfunction. This evidence comes from long-term registry reports and randomized clinical trials. With respect to heart failure (HF), there is registry, pilot trial, and randomized clinical trial evidence of safety and efficacy. This paper summarizes some of the mechanisms and outcomes of EECP in HF patients and helps to elucidate the role of EECP in the management of patients with chronic HF.

Counterpulsation↗

PubMed1992

Observations of coronary flow augmentation and balloon function during intraaortic balloon counterpulsation using transesophageal echocardiography.

The intraaortic balloon pump has been shown to decrease myocardial oxygen demand by afterload reduction, while increasing myocardial oxygen supply by diastolic augmentation of coronary blood flow. This diastolic augmentation of coronary flow has been demonstrated experimentally with invasive methods. Noninvasively, transesophageal echocardiography has demonstrated efficacy in enabling visualization of the proximal left coronary artery and in recording coronary blood flow velocity. To assess the potential of this technique in demonstrating quantitatively the increase in coronary flow during counterpulsation, 6 patients were studied during intermittent balloon pumping. 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). Problems associated with intraaortic balloon pumping were discovered by transesophageal echocardiography in 4 patients (incorrect balloon placement, damage to the aortic wall [2 patients], and premature balloon deflation time). Transesophageal echocardiography can be used in evaluating intraaortic balloon positioning within the aorta and in monitoring coronary artery flow augmentation during counterpulsation. This relatively noninvasive technique adds another dimension to the evaluation of balloon function and may help in optimizing the benefits of counterpulsation.

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PubMed2006

Enhanced external counterpulsation improves exercise tolerance in patients with chronic heart failure.

OBJECTIVES: The PEECH (Prospective Evaluation of Enhanced External Counterpulsation in Congestive Heart Failure) study assessed the benefits of enhanced external counterpulsation (EECP) in the treatment of patients with mild-to-moderate heart failure (HF). BACKGROUND: Enhanced external counterpulsation reduced angina symptoms and extended time to exercise-induced ischemia in patients with coronary artery disease, angina, and normal left ventricular function. A small pilot study and registry analysis suggested benefits in patients with HF. METHODS: We randomized 187 subjects with mild-to-moderate symptoms of HF to either EECP and protocol-defined pharmacologic therapy (PT) or PT alone. Two co-primary end points were pre-defined: the percentage of subjects with a 60 s or more increase in exercise duration and the percentage of subjects with at least 1.25 ml/min/kg increase in peak volume of oxygen uptake (VO2) at 6 months. RESULTS: By the primary intent-to-treat analysis, 35% of subjects in the EECP group and 25% of control subjects increased exercise time by at least 60 s (p = 0.016) at 6 months. However, there was no between-group difference in peak VO2 changes. New York Heart Association (NYHA) functional class improved in the active treatment group at 1 week (p < 0.01), 3months (p < 0.02), and 6 months (p < 0.01). The Minnesota Living with Heart Failure score improved significantly 1 week (p < 0.02) and 3 months after treatment (p = 0.01). CONCLUSIONS: In this randomized, single-blinded study, EECP improved exercise tolerance, quality of life, and NYHA functional classification without an accompanying increase in peak VO2.

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PubMed2000

Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction.

This study compared the hemodynamic effects of enhanced external counterpulsation and intra-aortic counterpulsation in patients with acute myocardial infarction. Results demonstrated similarity between these 2 methods, except enhanced external counterpulsation had a transient effect of increasing right atrial pressure, pulmonary capillary wedge pressure, and cardiac index.

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PubMed1996

A valveless high stroke volume counterpulsation device restores hemodynamics in patients with congestive heart failure and intractable cardiogenic shock awaiting heart transplantation.

The paraaortic counterpulsation device is a round pumping chamber with one valveless opening 20 mm in diameter and a 100 ml stroke volume. The paraaortic counterpulsation device was implanted on the ascending aorta of three male patients with intractable cardiogenic shock. Patients were assisted for 4 hours and 8 and 54 days, respectively; the first patient died as a result of nonresponding peripheral vasodilation and the other two died of septic shock. The two patients who were assisted for 8 and 54 days were conscious and able to function in a limited manner during the mechanical assistance. Discontinuation of the mechanical support for a few seconds was followed by low systolic arterial pressure (30 to 60 mm Hg) and syncopal episodes. Biochemical tests and autopsy results in these patients showed no evidence of blood cell destruction, thrombus formation, brain infarction, or other distal emboli. In conclusion, satisfactory hemodynamic effects, excellent biocompatibility, and simplicity of the implantation procedure in these patients encourage the use of the paraaortic counterpulsation device as a bridge to heart transplantation.

Adult↗

PubMedDate not supplied

The quest for permanent ventricular assistance: the role of aortic counterpulsation.

Temporary aortic counterpulsation is used routinely for the management of cardiogenic shock. By the perseverance of several investigators, permanent aortic counterpulsation is close to becoming a clinical reality. The initial clinical experience with permanent aortic counterpulsation (KCV) has demonstrated that it can be implanted with very low peri-operative morbidity and mortality. It is a novel non-obligatory device that has several advantages over other existing devices. There is no need for anti-coagulation and no valves or internal electronics that could fail and force VAD replacement. The control algorithm is simple, as the device is triggered "on-demand" by the electrical activity of the native heart. Furthermore, it is non-obligatory, so it can be turned on/off at will by the patient without increasing the risk of thromboembolic events. The disadvantages are that it provides only "partial" support. It increases cardiac output by approximately 40% depending on the afterload condition of the patient. It depends upon native heart activity to function and cannot be placed in patients with severe biventricular function, uncontrolled tachyarrhythmias, or with native valvular disease. However, the degree of support obtained seems sufficient to reverse the heart failure syndrome, improve end-organ dysfunction and remove inotrope dependency. The KCV is designed for intervention in NYHA class IV patients before there is severe biventricular failure or lack of any myocardial reserve. It would not be an acute recovery device or one in which IABP pumping does not improve hemodynamics. The KCV can be considered equivalent to a mechanical, permanent, non-energy depleting inotrope and may have a role in improving the length and quality of life in patients with end stage heart failure. By treating advanced CHF early, the KCV may reduce the number of patients progressing towards cardiac replacement therapy with transplantation or a total artificial heart.

Counterpulsation↗

PubMed2004

Enhanced external counterpulsation improves skin oxygenation and perfusion.

BACKGROUND: Enhanced external counterpulsation (EECP) augments diastolic and reduces systolic blood pressures. Enhanced external counterpulsation has been shown to improve blood flow in various organ systems. Beneficial effects on skin perfusion might allow EECP to be used in patients with skin malperfusion problems. This study was performed to assess acute effects of EECP on superficial skin blood flow, transdermal oxygen and carbon dioxide pressures. MATERIALS AND METHODS: We monitored heart rate, blood pressure, transdermal blood flow as well as oxygen and carbon dioxide pressures in 23 young, healthy persons (28 +/- 4 years) and 15 older patients (64 +/- 7 years) with coronary artery disease before, during and 3 min after 5 min EECP. Friedman test was used to compare the results of 90-s epochs before, during and after EECP. Significance was set at P < 0.05. RESULTS: Enhanced external counterpulsation increased heart rate and mean blood pressure. During EECP, transdermal oxygen pressure and concentration of moving blood cells increased while transdermal carbon dioxide pressure and velocity of moving blood cells decreased significantly in both groups. After EECP, transdermal carbon dioxide pressure was still reduced while the other parameters returned to baseline values. CONCLUSIONS: Improved skin oxygenation and carbon dioxide clearance during EECP seem to result from the increased concentration and reduced flow velocity, i.e. prolonged contact time, of erythrocytes. The increased concentration of moving blood cells and the decreased velocity of moving blood cells at both tested skin sites indicate peripheral vasodilatation.

Adult↗

PubMed1991

Complications of intraaortic balloon counterpulsation insertion in patients receiving thrombolytic therapy for acute myocardial infarction.

This study retrospectively examines 38 patients who presented with acute myocardial infarction requiring intraaortic balloon pump counterpulsation. Two groups of patients were identified. Group I consisted of patients with acute myocardial infarction treated with intraaortic balloon pump without thrombolytic therapy. Group II consisted of patients treated with intraaortic balloon pump after receiving intravenous thrombolytic therapy. These groups were compared and contrasted with regard to previously identified complications associated with intraaortic balloon pump counterpulsation including loss of limb and mortality. The need for surgery, embolectomy, and drainage of hematoma were also evaluated. The need for surgery in group II (11%) and in both groups combined (7%) is lower than is generally reported in literature (range 11.6% to 34%). In addition, no patients experienced a loss of limb and no patients in the study had severe life-threatening iatrogenic morbidity or mortality. While mortality was not an end point in this study, it was noted that there was an increased survival rate in group II patients with 61% surviving until the time of hospital discharge. Also, eight out of 14 patients in group II who underwent intraaortic balloon pump counterpulsation for cardiogenic shock survived until the time of discharge. This represents a 57% survival rate for patients presenting with cardiogenic shock. We conclude that intraaortic balloon pumps can be inserted safely following thrombolytic therapy in a community hospital.

Adult↗

PubMed1997

Skeletal muscle extra-aortic counterpulsation in dogs with dilated cardiomyopathy.

Skeletal muscle extra-aortic counterpulsation was performed in seven dogs with dilated cardiomyopathy. A left latissimus dorsi dynamic descending thoracic aortomyoplasty was used as the autologous counterpulsator. Pulse train stimulation in diastole was used to initiate contraction and fibre type transformation. Two of the dogs died within 48 hours of surgery. The device was successfully activated in the five remaining dogs, but in one individual it failed within 48 hours of activation. Serial echocardiographic examinations of dogs in which the device functioned successfully (n = 4) showed trends towards the decrease in the left ventricular systolic internal dimension, left ventricular diastolic internal dimension, E-point to septal separation and left atrial diameter in systole seven to 14 days following the procedure, although these changes failed to persist in the long-term. The results suggest that skeletal muscle for cardiac assistances such as extra-aortic muscle counterpulsation, might be a therapeutic option for dogs with cardiac failure due to dilated cardiomyopathy.

Animals↗

PubMed1994

Counterpulsation: historical background, technical improvements, hemodynamic and metabolic effects.

The intraaortic balloon counterpulsation is performed today on the same principles that were described in its first experimental use in 1962. Experimental studies have shown significant increase of the mean aortic diastolic pressure, the diastolic pressure-time index, endocardial viability ratio, cardiac output, ejection fraction, coronary cerebral and renal blood flow, lactate utilization and myocardial oxygen supply and significant decrease of the systolic aortic pressure, left-ventricular end-diastolic pressure, left-ventricular work, tension time index, myocardial oxygen consumption and lactate production. In similar studies, intraaortic balloon pump (IABP) decreases the size of myocardial infarction. New IABP driving systems, small size sheaths and balloon catheters for percutaneous insertion made the use of the IABP easier and safer. The paraaortic counterpulsation device is suitable for chronic mechanical assistance. It is more effective than the IABP and shows excellent biocompatibility in chronic experiments. Its clinical application in 3 patients showed excellent biocompatibility and promising hemodynamic effects. In conclusion, the salutary hemodynamic effects of the IABP have been shown in several experimental studies. The technical improvements and the development and use of new devices suggest that we still need to learn more about the usefulness of the counterpulsation technique.

Animals↗

PubMed1992

Improved regional myocardial blood flow, left ventricular unloading, and infarct salvage using an axial-flow, transvalvular left ventricular assist device. A comparison with intra-aortic balloon counterpulsation and reperfusion alone in a canine infarction model.

BACKGROUND: It has been suggested that left ventricular unloading at the time of reperfusion provides superior infarct salvage over reperfusion alone. The purpose of this study was to show that the Hemopump transvalvular axial-flow left ventricular assist device provides superior left ventricular unloading, ischemic zone collateral blood flow, and infarct size reduction compared with intra-aortic balloon counterpulsation and reperfusion alone. METHODS AND RESULTS: Eighteen dogs were instrumented with regional myocardial function sonomicrometers in the ischemic and control zones. The left anterior descending coronary artery just distal to the first diagonal branch was instrumented with a silk snare and Doppler flow probe. Additionally, pressure catheters were placed in the left atrial appendage, left ventricular apex, and ascending aorta for hemodynamic measurements. Regional myocardial blood flow was determined by using 15-microns radioactive microspheres. Measurements were made in the control state, immediately after coronary occlusion, at 1 and 2 hours after coronary occlusion, with reperfusion, and 1 hour after reperfusion. In treated animals, left ventricular assistance was maintained during the entire period of occlusion and reperfusion. The Hemopump was associated with a significant decrease in left ventricular systolic and diastolic pressure, whereas mean arterial pressure was maintained. Intra-aortic balloon counterpulsation resulted in no significant changes in left ventricular systolic pressure and a modest decrease in left ventricular diastolic pressure. Regional unloading as assessed by sonomicrometers was significant in the Hemopump animals and absent in the balloon pump animals. Absolute regional myocardial blood flow in the ischemic zone increased slightly (p = 0.002) in the Hemopump animals and did not change in the balloon pump animals. Infarct size expressed as percentage of the zone at risk was 62.6% in the control animals, 27.22% in the balloon pump animals, and 21.7% in the Hemopump animals. CONCLUSIONS: Mechanical unloading of the ventricle during ischemia and reperfusion appears to result in significant infarct salvage compared with reperfusion alone. The Hemopump appears to provide superior left ventricular systolic and diastolic unloading compared with intra-aortic counterpulsation in a canine model.

Animals↗

PubMed1990

Experimental and clinical evaluation of a counterpulsation device.

The counterpulsation technique has been widely used for the assistance of the acutely failing left ventricle utilizing the intraaortic balloon pump. However, a variety of other counterpulsation devices are available. To evaluate a counterpulsation device several variables need to be considered: (1) experimental and clinical determination of the salutary effects of the device on the left ventricular ejection fraction, cardiac output, aortic pressures, left ventricular end-diastolic pressure, tension-time index, diastolic pressure-time index and endocardial viability ratio; (2) experimental and clinical estimation of the device biocompatibility, and (3) the clinical improvement of the assisted patients.

Counterpulsation↗

PubMed1991

Intra-aortic balloon counterpulsation support in the high-risk cardiac patient undergoing urgent noncardiac surgery.

Patients with a recent myocardial infarction, congestive heart failure, sever angina, or uncorrected multivessel coronary artery disease are at increased risk of cardiac complications after major noncardiac surgery. Although invasive hemodynamic monitoring and preoperative optimization of cardiac status may lead to some reduction in the rate of perioperative cardiac events, the mortality from such events remains high. We report our experience with the use of perioperative intra-aortic balloon counterpulsation in eight patients with unstable coronary syndromes or severe coronary artery disease who underwent urgent noncardiac surgery. There were no perioperative cardiac events while the intra-aortic balloon pump (IABP) was in place. There were two postoperative cardiac events (non-fatal myocardial infarction, congestive heart failure) in the first postoperative week after the IABP was removed. One patient required emergent femoral thrombectomy as a result of intra-aortic balloon counterpulsation and subsequently died of a gastrointestinal hemorrhage. Intra-aortic balloon counterpulsation should be considered as an adjunct to maintain hemodynamic stability for the high-risk cardiac patient about to undergo urgent or emergent noncardiac surgery.

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