Coronary artery spasm and mitral valve prolapse.

Ten patients, representing 1.34 per cent of those patients undergoing selective coronary arteriography, were found to have unequivocal evidence of coronary artery spasm. This involved the proximal right coronary artery in eight patients, the mid-left anterior descending branch in one, and the left main coronary artery in one. Eight of these 10 patients had otherwise normal coronary arteries. Of these 10 patients with coronary artery spasm, nine had evidence of mitral valve prolapse. This involved the posteromedial scallop in six patients; the anterolateral and posteromedial scallops in one; the middle and posteromedial scallops in one; and the anterolateral, middle, and posteromedial scallops in one. These data suggest an association between coronary artery spasm and mitral valve prolapse. Coronary artery spasm may thus be an important factor in the pathogenesis of the chest pain, arrhythmias, electrocardiographic abnormalities, and sudden death, that have already been described in some patients with mitral valve prolapse.