The hemodynamic and metabolic effects of cardioplegic rearrest in the pig

The hemodynamic and metabolic effects of two consecutive 1-hour periods of cardioplegic arrest with a 20-minute interval of reperfusion or cardioplegic rearrest were evaluated in pig hearts. This model was designed to recreate in the laboratory a situation occasionally encountered during open-heart operation. Results indicate that at the end of 40 minutes of reperfusion following cardioplegic rearrest and 20 minutes after cardiopulmonary bypass (CPB), the stores of glycogen, adenosine triphosphate and total adenine nucleotides were lower than those found in hearts beating under CPB for an identical period of time. These stores were, however, sufficient to permit hemodynamic recovery, and they compared favorably with those found in hearts subjected to a single hour of cardioplegic arrest and reperfusion. The laboratory data and our previous clinical experience suggest that cardioplegic rearrest is a feasible alternative when surgical difficulties demand a second period of aortic cross-clamping after an initial period of cardioplegic arrest and reperfusion.