Coronary Artery Reperfusion

at postmortem 1 wk later. In control dogs, the gross infarct size at postmortem averaged 63.8±7.3% of that predicted from the acutely injured zone. However, in reperfused hearts the average gross infarct size at 1 wk was only 10.2+4.4% of that predicted. Transmural specimens were obtained at autopsy for histology and measurement of myocardial creatine phosphokinase (CPK) activity from sites initially used for epicardial electrocardiography. In control animals, there was a direct relationship between the degree of ST segment elevation and the degree of cell necrosis in transmural histologic sections. ST segment elevation also predicted myocardial CPK (international units per milligram protein): log CPK = 0.0613 ST + 1.17 (r = 0.66, n = 56 sites). In the reperfused animals, log CPK =0.166 ST + 1.36 (r = 0.69, n = 46 sites) showing almost complete preservation of CPK activity at 1 wk, sparing being most prominent in the epicardial zone. Similarly, there was a good correlation between myocardial CPK activity and the histological assessment of cell destruction, the degree of cell damage = 0.152 CPK + 3.86 (r = 0.86; n = 102 sites). Thus, control dogs showed severe myocardial CPK depletion Received for publication 3 April 1972 and itt revised form 30 June 1972. and histologic evidence of extensive cell destruction, whereas animals subjected to coronary artery reperfusion had little CPK depletion and much less evidence of myocardial cell necrosis 1 wk later.