The association between perioperative myocardial ischemia and infarction has clearly been established. In patients undergoing CABG, myocardial ischemia that occurs during the intraoperative period has the strongest correlation with perioperative MI. In noncardiac surgery, myocardial ischemia during the postoperative period is more significantly associated with ischemic cardiac morbidity than is ischemia that develops pre- or intraoperatively. Much of the descriptive phase of this research is complete. It is important next to determine the etiology of perioperative myocardial ischemia and to design treatment regimens that will tell us whether MI is merely associated with perioperative ischemia or is also the cause of cardiac morbidity.