Comparison of coronary arteriographic findings during angina pectoris associated with S-T elevation or depression.

Coronary arteriographic findings during an attack of angina pectoris associated with S-T segment elevation and angina associated with S-T depression were compared in 54 patients. Thirty-eight attacks with S-T segment elevation included 2 that were spontaneous, 6 induced by methacholine, 4 by epinephrine with or without propranolol, 9 by arm exercise, 5 by hyperventilation with or without Tris-buffer infusion and 12 by ergonovine maleate. Twenty-nine of the 38 attacks were associated with total occlusion, 8 with subtotal occlusion and 1 with diffuse narrowing of a major coronary artery caused by spasm. Twenty-six attacks with S-T segment depression included 3 induced by methacholine, 13 by arm exercise, 3 by hyperventilation with or without Tris-buffer infusion and 7 by ergonovine maleate. Eight of the 26 attacks were associated with subtotal occlusion and 9 with diffuse narrowing of a major coronary artery caused by spasm; 3 attacks were associated with total occlusion of a major coronary artery well supplied with collateral vessels and 2 with total occlusion of a small coronary branch caused by spasm. Four attacks were associated not with spasm but with fixed subtotal occlusion of a major coronary artery (3 attacks) or total occlusion of a major coronary artery receiving collateral vessels (1 attack). Only 2 of the 31 patients with S-T segment elevation had collateral vessels compared with 8 of the 16 patients with S-T segment depression (p less than 0.001). It is concluded that angina pectoris associated with S-T segment elevation usually indicates more severe myocardial ischemia than angina associated with S-T segment depression.