LAUSR

Myocardial injury is one of the leading causes of mortality within 30 days of noncardiac surgery. In fact, over one-third of perioperative deaths can be attributed to cardiac complications. Although most perioperative myocardial ischemic events occur within the first 72 hours after surgery, up to 20% occur intraoperatively. A substantial amount of research has been devoted to preoperative identification of at-risk patients and modifications of risk factors to avoid this complication; however, the incidence of perioperative myocardial infarction (PMI) remains between 0.3% and 36% depending on the population, study design, and definition used. In addition, a strong association between PMI and in-hospital mortality has been demonstrated, with in-hospital mortality rates between 12% and 40%. Despite the relative commonality of this intraoperative event, there is a paucity of evidence on intraoperative management. As experts in operating room crisis management, anesthesiologists must be proficient in the identification and management of intraoperative myocardial ischemia. Myocardial injury exists on a spectrum that ranges from a reversible defect (stunning) to an irreversible process that can progress to ventricular dysrhythmias or cardiogenic shock (infarction). The majority of PMIs are non-ST elevated acute coronary syndromes (NST-ACS), which usually result from an imbalance in the ratio of myocardial oxygen supply and demand. The basic tenets of management seek to restore this balance throughmedical management or procedural intervention. In each case, the benefits of reperfusion must be weighed against the risk of hemorrhage. This narrative review will summarize the pertinent anatomic and physiological considerations and seek to provide a framework on which to base the intraoperative management of myocardial ischemia.