LEFT-VENTRICULAR FUNCTION AFTER PRESERVING THE HEART FOR 2 HOURS AT 15-DEGREES-C

Abstract

Hearts preserved for 2 h at 15.degree. C were evaluated for maximum function with the use of an isolated working dog heart subjected to stress. Left ventricular function was determined by controlling aortic flow resistance and flow into the left atrium. Groups studied were hypothermia alone (H), hypothermia with a modified extracellular solution (H+DKS), hypothermia with a modified Collins solution (H+C), 6 periods of 20 min of hypoxic hypothermia followed by 10 min of blood reperfusion (H20+R10) and blood cardiplegia (BC). Hypothermia alone for 1 h was also evaluated. Functions were studied for 2 1/2 h following reperfusion by determining Starling''s curves for each heart. H alone gave adequate myocardial protection for only 1 h but not for 2 h. H20+R10 was better than H, but function was depressed. Use of H+C provided protection equal to H20+R10, but the hearts recovered function slowly. Only hearts preserved by H+DKS and BC for 2 h had normal function. Hearts from all groups except H+DKS and BC became edematous. Excellent function was obtained with DKS or BC following 2 h of ischemia at 15.degree. C. Initial clinical use of BC supported these laboratory findings.