Stress testing with ST-segment depression at rest. An angiographic correlation.

Near maximal graded exercise tests and coronary angiograms were compared in 37 patients with a history of chest pain and with ST segment depression at rest, who were free of obvious nonischemic causes of ST depression. Additional ST depression of 0.1 mV or more occurred with exercise in 26 patients and 23 of these had obstruction of one or more coronary arteries (sensitivity = 0.92). Eleven patients showed no additional ST-segment depression with exercise, and nine of these had normal coronary angiograms (specificity = 0.75). Patients with no increase in ST depression on exercise developed the highest heart rates; those with asymptomatic additional ST depression achieved intermediate rates; and those with anginal attacks during testing demonstrated the least heart rate acceleration. Those with less coronary obstruction exercised longer on the treadmill than those with more obstruction. Those showing added ST depression were predominantly men (18 of 26) and were older (mean 54 years) than those who did not (mean 44 years). No test complications were encountered. This study suggests that safe and effective stress testing may be accomplished not only in persons with normal resting ECGs but also in selected patients who have abnormal ST segments at rest.