FUNCTIONAL RECOVERY IN RABBIT HEART AFTER PRESERVATION WITH A BLOOD CARDIOPLEGIC SOLUTION AND PERFUSION

Thirty-five isolated rabbit hearts were subjected to 60 minutes of storage after cardiac arrest with high K+ crystalloid cardioplegic solution at 5-degrees-C. They were divided into five groups (n = 7 per group) according to the preservative protocol: group I (simple immersion in 0-degrees-C normal saline solution), group II (simple immersion in 30-degrees-C blood cardioplegic solution), group III (immersion and perfusion in 30-degrees-C blood cardioplegic solution), group IV (simple immersion in 10-degrees-C blood cardioplegic solution), and group V (immersion and perfusion in 10-degrees-C blood cardioplegic solution). After storage for 1 hour, cardiac function, tissue water content, and the number of hearts capable of ejecting against a 100 cm H2O column afterload were recorded and compared among the five groups. Cardiac function in group II was not different from group I. Aortic pulse pressure and left ventricular developed pressure were lower in group II than in group III, IV, or V. Aortic developed pressure was higher in groups III and V (p < 0.05). Tissue water content in group I was significantly higher than in groups II, III, and V (p < 0.05). All hearts in groups III and V could eject against a 100 cm H2O afterload after preservation (p < 0.05 versus groups I, II, and IV). Factorial analysis among the groups using blood cardioplegic solution showed that either hypothermia or perfusion alone or the combination was a protective factor in providing functional recovery of stored hearts. Blood cardioplegic solution with or without hypothermia and a continuous low-flow perfusion might provide a superior method of preservation of cardiac function during heart transplantation.