Coronary arterial spasm in angina at rest associated with transient ST-segment changes.

In order to clarify the role of coronary arterial spasm in the pathogenesis of angina at rest, coronary arteriography was perforned during spontaneous chest pain or following intravenous administration of ergonovine maleate in 40 patients with angina at rest. Coronary vasospasm was demonstrated in 23 patients with ST-segment elevation during chest pain (group I), in 7 with ST-segment depression (group II), and in 4 with both ST-segment depression and elevation (group III). Complete spastic occlusion of the proximal or of the midportion of the left anterior descending artery was always associated with ST-segment elevation in anterior leads. In contrast, transient ST-segment depression in anterior leads was associated with diffuse narrowing of the left anterior descending artery with slow progression of the contrast medium, or complete occlusion of a small branch or of the distal segment of the left anterior descending artery. ST-segment elevation in inferior leads was associated with complete spastic occlusion or with significant spastic narrowing of the right coronary artery or of the circumflex artery. We conclude that coronary spasm can be demonstrated in a selected cohort of patients with angina at rest associated with transient ST-segment changes. In some cases the site and the severity of the spasm may produce varying degrees of ischemia, thus determining the direction of the ST-segment shift.