Coronary-artery spasm immediately after myocardial revascularization: recognition and management.

We investigated coronary-artery spasm in six patents who had had unexpected hemodynamic collapse within two hours after cardiopulmonary bypass for myocardial revascularization. All six had profound hypotension and recurrent ST-segment elevation in electrocardiographic Leads II, III, and aVF. All had either normal or noncritical luminal irregularities of dominant right coronary arteries and more than 75 per cent occlusions in the left coronary circulation. Right-coronary-artery spasm, which was reversed after intracoronary nitroglycerin, was demonstrated angiographically in one patient; a patent right coronary artery was found at autopsy in another patient. Three patients died despite large intravenous doses of nitroglycerin. Two patients who had been unresponsive to intravenous nitroglycerin recovered after direct infusion of nitroglycerin into the right coronary artery. Coronary-artery spasm immediately after myocardial revascularization may cause circulatory collapse and death; although the spasm may be refractory to usual therapy, it may respond to intracoronary nitroglycerin.