Use of Exercise Testing for Diagnostic and Functional Evaluation of Patients with Arteriosclerotic Heart Disease

Abstract

Myocardial oxygen demand generally increases with increasing levels of energy expenditure, but several factors which modify this relation must be considered, both in the design of the test methods and in interpretation of results of exercise tests in patients with arteriosclerotic heart disease (ASHD). A wide variety of exercise test methods are currently used. Master's test is simple to perform and requires no elaborate equipment. It has been more widely employed than any other test and much clinicopathologic and correlative data are available. However, Master's test provides little information on the patient's physical work capacity. Multistage tests, carried to a symptom-limited or maximal/near-maximal workload level, provide quantitative data on physical performance capacity and also result in fewer false-negative ECG responses among patients with ASHD. Follow-up studies of asymptomatic subjects have demonstrated that a horizontal S-T depression during or after exercise is associated with a high risk of developing clinical ASHD. The prognostic significance of the exercise test appears to be independent of other known risk factors. Studies correlating the ECG response to exercise with findings at coronary angiography have demonstrated an abnormal ECG response in 0-30% of patients with no demonstrable arterial disease. The number of patients with significant coronary artery disease and negative ECG response tends to be higher. Evaluation of physical performance capacity is the primary indication for exercise testing in patients with known ASHD. The results of the test form a basis for recommendations on occupational and recreational physical activity. Serial tests may be used to evaluate objectively the effect of medical and surgical therapy.