Coronary artery spasm in a patient with unstable angina pectoris.

A 32-year-old male with the clinical syndrome of unstable angina is presented. During cardiac catheterization and coronary cineangiography, the coronary arteries were found to be free of atherosclerosis, but segmental spasm of the right coronary artery was observed. Spasm was reproduced, but to a milder degree, upon the administration of ergonovine maleate intravenously. The patient was discharged on a regimen of oral nylidrin HCL, with symptomatic improvement.