Incidence of myocardial ischemia during carotid endarterectomy.

Since patients undergoing carotid endarterectomy often suffer from coronary artery disease, the detection, adequate treatment and prevention of intra and postoperative myocardial ischemia are a major concern. Effectively, the deleterious effects of intraoperative ischemic episodes have been largely documented. They may lead to arrhythmia, left ventricular dysfunction lasting several hours or myocardial infarction. Anesthesia induced by fentanyl, flunitrazepam and pancuronium and maintained with N20 and volatile anesthetics when warranted, has the advantage of preventing cardiovascular stimulation during endotracheal intubation and surgery, and of significantly decreasing the incidence of intraoperative myocardial ischemia in patients suffering from mild angina pectoris. However, with this approach, the incidence of intraoperative ischemic episodes remains high in patients suffering from disabling angina pectoris. In such cases, prophylactic i.v. nitroglycerin, administered continuously at the dose of 0.7 microgram/kg-1/min-1, optimizes myocardial oxygenation during surgery and minimizes the risk of intraoperative myocardial ischemia.