Comparison of crystalloid and sanguineous cardioplegic solutions in the dog

Myocardial protection provided by 2 types of cold cardioplegic solution and by cold saline solution was compared experimentally in dogs on cardiopulmonary bypass. Techniques and solutions used simulated clinical conditions. Serial biopsies of myocardium were assayed for adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate. Maintenance and recovery of each phosphate was calculated as a percentage of the prebypass value for each type of solution; these values were used to compare the myocardial protection afforded by the 3 solutions. A difference in these values was not observed between the 2 types of cardioplegic solution; both values were greater than for the control solution, which may indicate improved myocardial protection with cardioplegic arrest.