Continuing medical education: Diagnostic and prognostic value of exercise testing
Exercise testing is useful in evaluating suspected or proven coronary artery disease (CAD) and provides evidence for or against latent myocardial ischemia. The pretest probability of CAD is dependent on sex, age, and symptoms. Exercise testing modifies this probability by increasing it or decreasing it, depending on whether the test is positive or negative. Recording multiple leads both during and after exercise improves sensitivity, specificity, and positive and negative predictive values. Patients with a shorter duration of exercise before developing ST-segment depression, with a greater degree of ST-segment depression, with a lower maximal heart rate during exercise, with exercise-induced down-sloping ST-segment depression, with ST-segment depression persisting after eight minutes into the recovery period, with angina associated with a positive exercise test, and with an abnormal blood pressure response to exercise have more severe CAD. Exercise testing is a useful prognostic indicator of subsequent coronary events in patients with and without evidence of prior myocardial infarction. Low-level treadmill exercise testing within three weeks of an uncomplicated acute myocardial infarction can identify patients at high risk for sudden cardiac death and recurrent myocardial infarction. Exercise testing is also useful in evaluating the effects of drugs, surgical treatment, and exercise programs in patients with CAD. © 1983 The American Burn Association.