We tested the ability of various cardiac preservation techniques to preserve left ventricular function of isolated canine hearts using preservation temperatures of 4 degrees or 15 degrees C. The four techniques tested were: (1) topical
hypothermia, and hypothermic arrest induced by (2) perfusion of 1 liter of a modified
Collins solution, (3) perfusion of 1 liter of a modified extracellular
solution (DKS), or (4) perfusion of 500 ml of blood
cardioplegia. Following the cold ischemia period, the hearts were reperfused with blood in the working heart preparation and tested for their ability to recover left ventricular function. Hearts preserved 2 hours at 15 degrees C using
hypothermia, modified
Collins solution, or DKS
solution achieved an average of 60, 73, and 95%, respectively, of baseline function. Hearts preserved 3 hours at 4 degrees C using topical
hypothermia attained 70% of baseline function, while hearts stored 5 hours at 4 degrees C using modified
Collins solution or DKS
solution recovered 83 and 92%, respectively, of baseline function. Hearts preserved at 4 degrees C functioned at levels equal to or greater than that of hearts stored at 15 degrees C, even though the hearts preserved at 4 degrees C were stored for longer periods than those preserved at 15 degrees C. Hearts preserved with blood
cardioplegia for 2 hours at either 4 degrees or 15 degrees C achieved functions statistically the same as baseline levels during the reperfusion period. These data show no advantage for preservation temperatures of 15 degrees C compared with 4 degrees C. Our data provide a firm experimental basis for the clinical use of myocardial preservation temperatures of 4 degrees C, especially when combined with
cardioplegia.