WHITHER ST SEGMENT DURING EXERCISE

The ST-segment response to exercise is generally highly accurate in predicting the presence or absence of coronary disease. This conclusion was questioned in the light of recent coronary angiographic studies of asymptomatic subjects with positive exercise tests. The low predictive accuracy of a positive exercise test in the angiographic studies of asymptomatic subjects is entirely compatible with the conclusions of epidemiologic studies, once the difference between risk ratio and predictive accuracy is appreciated. The value of the ST-segment response to exercise stress testing as an aid in the diagnosis of coronary artery disease should be more carefully defined: it is of limited diagnostic value in symptomatic patients with a history of typical angina pectoris or a previously documented myocardial infarction. To distinguish between true positive and false positive ST-segment responses to exercise, a physician who elects to conduct routine screening exercise tests also should be prepared to proceed with coronary arteriography despite its attendant inconvenience, cost and risk.