To evaluate the efficacy of University of Wisconsin solution for clinical heart transplantation, load-independent parameters were used to assess left ventricular function after transplantation. Donor hearts were arrested with and stored in buffered cold cardioplegic solution for control (n = 5) and University of Wisconsin solution for the experimental group (n = 5). Orthotopic transplantations were performed in a routine manner. Mean donor age (cardioplegic solution, 28 +/- 5.2 years; University of Wisconsin solution, 28 +/- 5.1 years) and ischemic times (cardioplegic solution, 181 +/- 27 minutes; University of Wisconsin solution, 224 +/- 23 minutes) were similar. Two hours after reperfusion of the heart, transesophageal echocardiography was used to image the left ventricle at the mid-papillary muscle level, and a high-fidelity catheter-tipped manometer was placed in the left ventricle to record left ventricular pressure simultaneously. These images were digitized during apneic baseline conditions and during an acute reduction in preload from inferior vena caval occlusion. The left ventricular cross-sectional areas were measured and matched with left ventricular pressure from the catheter-tipped manometer to reveal pressure-area relationships. The baseline parameters fractional area change and stroke force were calculated. End-systolic elastance, the slope of end-systolic pressure-area relationship and preload recruitable stroke force, the slope of stroke force versus end-diastolic area were calculated from the inferior vena cava occlusion measurements.(ABSTRACT TRUNCATED AT 250 WORDS)