Arthur R. Kantrowitz

Clinical and Hemodynamic Results of Intraaortic Balloon Pumping and Surgery for Cardiogenic Shock

The AVCO balloon pump has been employed in treating 40 patients with cardiogenic shock from acute myocardial infarction (CS-MI). All patients were given a trial of medical therapy with hemodynamic monitoring. The time from the development of shock to institution of intraaortic balloon pumping (IABP) was less than 24 hours in all but nine patients. Prior to IABP the mean hemodynamic values were: cardiac index (CI) 1.7 liters/min/m2; mean arterial pressure (MAP) 66 mm Hg; pulmonary artery wedge pressure (PAW) 22 mm Hg. After 24-48 hours of IABP the CI and MAP had increased 0.8 liters/min/m2 and 8 mm Hg, respectively, and the PAW had decreased 4.8 mm Hg. During IABP the shock syndrome was reversed in 31 patients. Four of 25 patients treated with IABP alone survived to be discharged, but two have died from subsequent infarctions. Because of the persistent high mortality, 15 patients judged unable to survive off IABP have undergone emergency surgical procedures with IABP continuing during preoperative angiography and postoperatively. Six were long-term survivors. It is concluded: (1) IABP is a safe, effective means of supporting the circulation in CS-MI; (2) IABP alone will improve survival in some patients; (3) IABP can provide circulatory support during angiography and the perioperative period in patients requiring revascularization for survival; and (4) some patients with CS-MI have myocardial necrosis too extensive to permit survival without permanent circulatory assistance or total cardiac replacement.

Effects of Intra-Aortic Balloon Counterpulsation on Cardiac Performance, Oxygen Consumption, and Coronary Blood Flow in Dogs

The effect of intra-aortic Counterpulsation (IACP) with a balloon upon myocardial oxygen consumption (MV·o2), coronary blood flow (TCF), and left ventricular performance was studied in 23 anesthetized canine right heart bypass preparations at constant heart rate and cardiac output. In nonhypotensive, nonTCF-limited preparations, IACP produced a fall in left ventricular peak systolic pressure (LVP) and a decrease in MV·o2 (-1.1 ± 0.2 (SE) ml/min/100 g LV). In these animals there was little steady state change in TCF (-5.6±5.9 ml/min), secondary to autoregulation by the coronary vascular bed. Left ventricular end-diastolic pressure (LVEDP) fell if elevated but exhibited little change if initially normal. However, in hypotensive preparations, in which left ventricular performance was substantially limited by a decreased TCF, IACP produced a striking increase in TCF (+40.9 ± 8.6 ml/min) accompanied by an increase in MV·o2 (+1.2±0.3 ml/min/100 g LV). Elevated LVEDPs fell substantially toward normal. Directiona...

Hemodynamic evaluation of intra-aortic balloon pumping in man.

Intra-aortic balloon pumping is effective in reducing left ventricular peak systolic pressure and increasing cardiac output in patients with severe cardiogenic shock secondary to acute myocardial infarction. Associated with these effects is a reduction in intravenous catecholamine requirements and increased sensitivity to diuretics. Reduction in left ventricular end-diastolic pressure is implied by improvement in arterial blood gas saturation (reduced arterioalveolar gradient) and was shown directly in one patient. Total myocardial oxygen consumption is probably reduced by counterpulsation. Platelet levels have not fallen significantly with adequate heparinization and the slow infusion of low molecular weight dextran. No complications have occurred related to femoral artery cannulation, nor has there been significant damage to the aorta. The findings suggest that this system is a safe means of assisting the failing left ventricle. The high mortality in this series (seven of eight patients) is related to the extent of irreversible myocardial damage which may be reduced by more aggressive, earlier application of counterpulsation.

Effects of Intra-aortic Balloon Pumping on Coronary Flow and Metabolism in Man

Coronary blood flow (CBF) and myocardial oxygen consumption (MVO2), myocardial lactate extraction, blood gases, and hemodynamics were measured on and off intra-aortic balloon pumping (IABP) 14 times in 10 patients during treatment of cardiovascular collapse following myocardial infarction. At the time of study an average of 14 hours of IABP had elapsed and all but one patient had stabilized out of cardiogenic shock. With IABP, CBF fell in 7 instances, was unaffected in 3, and rose in 4. Changes in MVO2 correlated closely with the observed effects on CBF. Lactate extraction and blood gases were not significantly affected. Systolic arterial pressure fell an average of 11 mm Hg with IABP, while mean diastolic pressure rose 8 mm Hg.These results suggest that the net result of IABP on coronary flow and metabolism depends on the interplay between increased blood flow to ischemic areas provided by increased diastolic perfusion pressure and diminution of blood flow to normal myocardium in which the oxygen requirements are reduced by diminished afterload.

Effects of intra-aortic balloon counterpulsation on cardiac performance, oxygen consumption, and coronary blood flow

The effect of intra-aortic Counterpulsation (IACP) with a balloon upon myocardial oxygen consumption (MVo2), coronary blood flow (TCF), and left ventricular performance was studied in 23 anesthetized canine right heart bypass preparations at constant heart rate and cardiac output. In nonhypotensive, nonTCF-limited preparations, IACP produced a fall in left ventricular peak systolic pressure (LVP) and a decrease in MVo2 (−1.1 ± 0.2 (SE) ml/min/100 g LV). In these animals there was little steady state change in TCF (−5.6±5.9 ml/min), secondary to autoregulation by the coronary vascular bed. Left ventricular end-diastolic pressure (LVEDP) fell if elevated but exhibited little change if initially normal. However, in hypotensive preparations, in which left ventricular performance was substantially limited by a decreased TCF, IACP produced a striking increase in TCF (+40.9 ± 8.6 ml/min) accompanied by an increase in MVo2 (+1.2±0.3 ml/min/100 g LV). Elevated LVEDPs fell substantially toward normal. Directionally similar changes in LVEDP could be produced by increasing TCF alone in the absence of balloon pumping. When TCF was maintained constant in the hypotensive, TCF-limited preparation, IACP produced a fall in peak LVP and LVEDP. These data document two effects of intra-aortic balloon Counterpulsation upon cardiac dynamics: (1) IACP can decrease left ventricular peak systolic pressure and LVEDP independent of changes in coronary flow; (2) a major effect of IACP in the hypotensive, failing, TCF-limited preparation is to improve cardiac performance by increasing TCF with an associated increase in MVo2.

Selective coronary and left ventricular cineangiography during intraaortic balloon assist for cardiogenic shock

Eleven patients underwent selective coronary and left ventricular cineangiography during intraaortic balloon pumping for acute myocardial infarction and cardiogenic shock. Studies were performed when the clinical and hemodynamic trend predicted in-hospital death. Angiograms were reviewed by dividing the left ventricle into six segments, each with its characteristic coronary perfusion. No patient with avascular and akinetic segments survived with or without surgery. One patient with residual perfusion of all segments showed massive necrosis at operation that eventually led to his death. In four patients the findings of residual contraction and perfusion of most segments suggested reversible ventricular dysfunction. Three of these underwent coronary surgery with two excellent survivors.