Two step exercise test as a test of cardiac function in chronic rheumatic heart disease and in arteriosclerotic heart disease with old myocardial infarction

Abstract

1. 1. The electrocardiographic responses of ninety-two consecutive patients with rheumatic heart disease and 100 consecutive patients with arteriosclerotic heart disease who performed a standard two step Master exercise test were analyzed for changes in mechanism, conduction and repolarization and evaluated by five sets of criteria. 2. 2. The incidence of abnormal responses according to the various criteria ranged from 18 to 48 per cent. However, there was no significant difference in the incidence or types of abnormal electrocardiographic responses to exercise in rheumatic or arteriosclerotic heart disease when compared with the same criteria. 3. 3. The incidence of abnormal responses varied according to the severity of disease as measured by the functional and therapeutic classification, regardless of the cause. The incidence of abnormal responses of patients with rheumatic heart disease was not related to age, type of valvular lesion or digitalis medication, but was directly related to the functional status of the heart as determined by the therapeutic and functional classification, cardiac chamber enlargement, presence of atrial fibrillation and electrocardiographic response to the Valsalva maneuver. Abnormal electrocardiographic responses also occurred more commonly in patients with anterior myocardial infarction. 4. 4. We challenge the belief that abnormal electrocardiographic changes occurring after exercise are either diagnostic of coronary arteriosclerosis or caused solely by an insufficient blood supply to the myocardium. Reasons are presented why the interreaction of many facets of myocardial function should be considered in the understanding of the changes produced by exercise. 5. 5. The two step exercise test is a valuable test of cardiac function but is not specific for the diagnosis of cause. The test has proved to be of value as an objective measure of circulatory fitness for brief peak exercise and has been useful for prescribing work and daily activities for patients with all types of heart disease.