Upsloping S-T segments in exercise stress testing. Six year follow-up study of 438 patients and correlation with 248 angiograms.

A 6 year follow-up study of 438 patients who underwent maximal treadmill stress testing revealed the following annual incidence rate of coronary events (death, myocardial infarction or onset or progression of angina pectoris): 13 percent in 84 subjects whose stress test produced 2 mm downsloping S-T segment depression, 9 percent in 230 subjects with 2 mm horizontal S-T depression and 9 percent in 124 subjects who had an upsloping S-T segment with 2 mm S-T depression measured 0.08 second from the J point. Coronary angiograms were obtained in another group of 248 subjects who underwent maximal treadmill stress testing. They revealed major (greater than 50 percent) obstruction of two or three vessels in 67 percent of 62 subjects with a downsloping S-T pattern on the stress test, in 60 percent of 116 subjects with horizontal S-T depression and in 57 percent of 70 subjects with upsloping S-T depression. Patients with an upsloping pattern of S-T depression during stress testing had the same incidence of coronary events as those with a horizontal pattern of S-T depression. Upsloping S-T depression should not be confused with isolated J point depression. Subjects with an upsloping segment also had the same incidence of major two or three vessel disease as those with horizontal depression. Subjects with a downsloping pattern has a slightly greater incidence of coronary events and major two or three vessel disease.