Myocardial protection for coronary artery bypass in patients with acute myocardial infarction: resuscitation of ischemic myocardium

Abstract

An increasing body of evidence suggests that the majority of myocardial injury that occurs during ischemia and reperfusion is effected during the reperfusion phase. There is also convincing evidence that controlling the conditions of reperfusion and composition of the reperfusate can markedly minimize the ultimate injury following an ischemic insult. Medical reperfusion (PTCA, thrombolytics) has the disadvantage of reperfusing with unmodified whole blood under uncontrolled conditions, whereas surgical reperfusion allows very stringent control of both. A brief review of the pathophysiology of ischemia and reperfusion is presented to gain insight into the mechanisms of injury that can be counteracted by controlling the conditions of reperfusion and composition of the reperfusate. Surgical protocols that have been developed independently at two separate institutions are outlined, along with the experimental data supporting each method, and the advantages and disadvantages of each method. This information should allow implementation of a rational plan of myocardial protection for resuscitation of the ischemic myocardium when performing coronary artery bypass grafting in the setting of acute myocardial ischemia and infarction.