24-HOUR INTERMITTENT PERFUSION STORAGE OF THE ISOLATED RAT-HEART - THE EFFECT OF PERFUSION INTERVALS ON FUNCTIONAL PRESERVATION

We investigated the effect of intermittent perfusion intervals on hear t preservation. The isolated rat heart was flushed with a cardioplegic solution, CP-11EB, and stored at 0-degrees-C for 24 hours. During sto rage, the heart was perfused periodically at 60 mm Hg for 3 minutes wi th 25-degrees-C oxygenated CP-11EB. The perfusion schedules were as fo llows: group I, every 4 hours; group II, every 6 hours; group III, eve ry 8 hours; group IV, every 10 hours; group V, 10 and 17 hours of stor age; group VI, every 11 hours. Poststorage function was assessed after 30 minutes of working reperfusion. Function of the unstored hearts in cluding aortic flow (51.5 +/- 2.5 ml/min), coronary flow (24.5 +/- 1.3 ml/min), cardiac output (75.6 +/- 3.0 ml/min) and work (85.0 +/- 5.4 g-m/min) served as controls. Group V hearts were best preserved with a ortic flow recovered to 65%; coronary flow 44%; cardiac output 58%; an d work 53% of the control. Recovery in group IV was comparable with gr oup V. Groups I, II, III, and VI recovered significantly less than gro up V. Myocardial adenosine triphosphate content (micromoles per gram d ry) in group V was 23.8 +/- 1.7, 20.8 +/- 0.9, 13.5 +/- 2.4, and 15.0 +/- 4.0, at 0, 10, 17, and 24 hours of storage, respectively. Intermit tent perfusion at 10 and 17 hours elevated adenosine triphosphate to 9 9% and 88% of prestorage level. Poststorage reperfusion did not improv e adenosine triphosphate content (16.2 +/- 2.4) over the end-storage l evel. Lactate dehydrogenase release during storage correlated linearly with the recovery of cardiac output in groups I, V, and VI. In summar y, the isolated rat hearts were best preserved with intermittent perfu sion at 10 and 17 hours of storage.