The myocardial recovery mode after cold storage for transplantation with Collins' solution and cardioplegic solution. A functional and metabolic study in the rat heart.

Mechanisms and kinetics of the effects of the ionic composition of two different storage solutions, an intracellular type and an extracellular type, were analyzed by examining the myocardial functional and metabolic recovery processes during the early reperfusion periods after 3 hours of cold storage using an isolated perfused working rat heart model. The hearts were stored either in our own cardioplegic solution (group 1) or in Collins' solution (group 2) for 3 hours at 4 degrees C and were then reperfused. The electromechanical activity in group 1 was elevated, as indicated by a higher incidence of ventricular fibrillation at 5 minutes of reperfusion (group 1: 5/6; group 2: 0/5; p < 0.05). The coronary flow rate in group 2 was significantly lower, at least for the first 15 minutes after reperfusion, than that of group 1, suggesting the possible existence of vasoconstriction in group 2. Although myocardial oxygen uptake during this period was smaller in group 2, the recovery of myocardial high-energy phosphate levels was better and creatine kinase leakage was less in group 2. The recovery of aortic flow after 30 minutes of reperfusion was significantly better in group 2 (group 1, 59.1 +/- 5.8%; group 2, 71.7 +/- 6.0%; p < 0.01), although the early recovery was somewhat worse in group 2. These data suggest that the heart stored in an intracellular-type solution, compared with one stored in an extracellular-type solution, recovers in an electromechanically suppressed fashion during the early reperfusion phase, associated with a better metabolic recovery and a slower but larger functional recovery. The disadvantage of the intracellular-type solution, however, may be its effect on the increase of coronary vascular resistance during the early reperfusion period.