The effects of intra-aortic counterpulsation on cardiac performance and metabolism in XXXX associated with @entity583 .

@entity1 @entity296 @entity301 @entity1457 @entity26 @entity880 @entity583 @entity2388
The effect of intra-aortic counterpulsation (IACP, 22-94 hr) on hemodynamics and cardiac energetics was evaluated in 10 @entity1 in @entity1457 after @entity583 . The data clearly indicate that IACP improves myocardial oxygenation, enhances peripheral perfusion, and probably improves myocardial contractility in the severely diseased heart. Before treatment, decreases in cardiac index (mean value, 1.22 liter/min per m(2)), systolic ejection rate (67 ml/sec), and time-tension index per minute (1280 mm Hg.sec/min) were observed. Systemic vascular resistance varied widely. Low coronary blood flow (68 ml/min per 100 g) was associated with increased myocardial @entity26 extraction (79%), low coronary sinus @entity26 tension (20 mm Hg), and abnormal myocardial @entity880 - @entity2388 metabolism. During 4-6 hr of IACP, systolic pressure and left ventricular outflow resistance decreased by 18% and 24%, respectively, while cardiac index improved by 38%. Diastolic arterial pressure rose 98%. Increase in coronary blood flow from an average of 68 to 91 ml/100 g per min (P < 0.001) was significantly correlated with rise in mean arterial pressure (r = 0.685). This correlation was best expressed in a third-order curve, which intercepts the point of no flow at a mean aortic pressure of 30 mm Hg. The flow-pressure curve is relatively flat above 65-70 mm Hg, but becomes steeper as mean aortic pressure falls below this point. Myocardial @entity26 consumption remained essentially unchanged during early IACP and tended to rise during the later stages. However, the relationship of cardiac work performed to @entity26 availability was markedly improved. Myocardial lactate production of 6% shifted to 15% extraction (P < 0.001). After termination of IACP, hemodynamics and myocardial perfusion and metabolism remained improved in the four @entity1 who could be reevaluated. Although the acute @entity1457 state was reversed in all @entity1 , only one left the hospital. Extensive @entity296 limits the long-term survival of such @entity1 . Therefore early IACP seems desirable, when subtle evidence of pump failure after @entity583 occurs. Early use of IACP may prevent the development of severe @entity301 or may stabilize cardiac energetics in severe @entity1457 facilitating subsequent surgical intervention.
