C ORON ARY ARTERY spasm, also known as Prinzmetal's angina, is characterized by severe recurrent attacks of angina and reversible ST segment elevation in patients at rest. Although the mechanism(s) of coronary artery spasm is not yet fully understood, transcellular or intracellular calcium translocation abnormalities are considered to play a pivotal role in its development.' This hypothesis has been supported by evidence that calcium channel blockers are highly effective for preventing anginal attacks in patients with coronary artery spasm.'
Severe circulatory collapse during the perioperative period may be induced by coronary artery spasm. Although this entity has been increasingly recognized as a serious complication of coronary artery bypass surgery in recent years."? reports on perioperative coronary artery spasm during other kinds of surgery have been limited." Therefore, four cases of coronary artery spasm during noncoronary artery surgery are described. In one patient, the coronary artery spasm was resolved after correction of respiratory alkalosis and intravenous (IV) administration of isosorbide dinitrate. In the other three patients, the coronary artery spasm was successfully treated by IV administration of nitroglycerin plus nicardipine.
CASE REPORTS
Four patients developed intraoperative coronary spasm in this hospital between March 1988 and August 1989 (Table I). During this period 4,400 patients underwent surgery under general anesthesia. The criteria for a diagnosis of coronary artery spasm were as follows: (I) reversible, marked ST segment elevation, and (2) concomitant severe hypotension that could not be explained by other factors such as anesthetic technique, surgical manipulation, or hemorrhage.'
Patient 1
A 56-year-old woman underwent mitral valve replacement under high-dose fentanyl anesthesia (100 ~g/kg).9