The optimal temperature for 24-hour heart preservation using continuous coronary perfusion method

This experiment was designed to compare three preservation temperatures, 0 degrees C, 4 degrees C, and 10 degrees C, in 24-hour heart preservation using a continuous coronary perfusion method in terms of myocardial extracted enzymes during preservation (CPK, LDH, and GOT), left ventricular (LV) function at reperfusion and ultrastructural changes both at the end of preservation and at reperfusion. Rabbit hearts were preserved at 0 degrees C (n = 6), 4 degrees C (n = 6), and 10 degrees C (n = 6) for 24 hours and reperfused with arterial blood from the abdominal aorta of support rabbits. The value of CPK in the 10 degrees C group was statistically higher than those of the 0 degrees C group or 4 degrees C group (p less than 0.05: 0 degrees C vs 10 degrees C, p less than 0.025: 4 degrees C vs 10 degrees C). Left ventricular developed pressures (LVDPs) at 60 minutes after reperfusion in the 4 degrees C group were statistically greater than those in the 0 degrees C group and 10 degrees C group at several LV balloon volumes (p less than 0.005: 4 degrees C vs 0 degrees C or 10 degrees C). Electron-microscopic examination at reperfusion demonstrated remarkably swollen mitochondria associated with disruption of cristae in the 0 degrees C and 10 degrees C groups, but much less morphological change in the 4 degrees C group throughout preservation and reperfusion. From an overall view point of these enzymatic, functional and ultrastructural results, 4 degrees C proved to be a superior preservation temperature of choice for prolonged heart preservation.