Increased coronary blood flow and cardiac contractile efficiency with intraaortic balloon counterpulsation in a porcine model of myocardial ischemia-reperfusion injury.

The evaluation of the impact of intraaortic balloon pump (IABP) on postischemic coronary perfusion and myocardial contractile impairment has been so far limited to early reperfusion phase. Therefore, we analyzed the 24-hour effects of IABP on coronary blood flow (CBF) and left ventricular performance in an animal model of acute myocardial ischemia-reperfusion injury. Healthy swine (n = 20) underwent 120-minute ligation of the left anterior descending coronary artery followed by 24 hours of reperfusion. We randomly assigned the animals to have IABP placed in the descending aorta 5 minutes after reperfusion onset (n = 10) or to undergo no implantation (n = 10). We measured CBF, coronary resistance, cardiac cycle efficiency (CCE), and maximal pressure/time ratio before ischemia was induced and at 30 minutes and 1, 6, 12, and 24 hours after reperfusion began. During diastole, CBF was significantly increased in IABP compared with baseline and controls at all time points (all p < 0.001). This was also true during systole in IABP only for the first hour after reperfusion began. Additionally, both CCE and pressure/time ratio were significantly increased in IABP compared with baseline at 30 minutes and 1 hour after reperfusion began (p < 0.001). IABP was associated with enhanced CBF and cardiac efficiency in a model of acute ischemic-reperfusion injury.