Intermittent coronary spasm during graded exercise.

We report a patient with Prinzmetal's angina with nearly normal coronary angiogram who not only developed severe myocardial ischemia during exercise, documented both electrocardiographically (ST elevation) and scintigraphically (with thallium-201), but also did so intermittently as the graded exercise progressed. Diagnostic coronary angiography showed spontaneous focal spasm of the proximal left anterior descending coronary artery. This unique response to exercise in a patient with variant angina suggests that factors other than catecholamine stimulation alone are active and rapidly attenuated in some patients. This phenomenon could be overlooked without appropriate electrocardiographic monitoring.