Angina pectoris and acute myocardial infarction due to "slow-flow phenomenon" in nonatherosclerotic coronary arteries: a case report.

A 51 year-old White woman with angina pectoris and nonatheromatous coronary artery disease is presented. Cardiac catheterization demonstrated a "slow-flow phenomenon" in the left coronary artery accompanied by severe angina pectoris and anterolateral ST-segment elevation and culminating in an acute nontransmural myocardial infarction. At repeat coronary arteriography, ergonovine maleate provocation proved negative. This patient is unique, since the previously documented 6 cases with this coronary cineangiographic response did not exhibit angina pectoris or ECG evidence of myocardial ischemia during the "slow-flow phenomenon," and none was complicated by an acute myocardial infarction. Various aspects of the pathophysiology of angina pectoris in this patient, including the recently described "reduced vasodilator reserve" concept, are briefly outlined.