A simplified system was developed for administration of blood cardioplegia with reperfusion modification. This system utilizes a single pass stainless steel coil to eliminate the need for a separate heat exchanger circuit. This system was compared with an oxygenated crystalloid cardioplegia system which was utilized in a manner which allowed warm blood perfusion of the heart for the last three minutes of the crossclamp interval. Both of these systems were compared with regard to mortality, spontaneous defibrillation, myocardial temperature, blood usage and peak CK-MB levels. In this series of patients, no significant advantage of either system could be identified.