Impaired Maximal Exercise Performance with Hypertensive Cardiovascular Disease

Responses to a multistage treadmill test of maximal exercise were studied in 61 hypertensive patients: 13 had uncomplicated hypertension; 15 had associated retinopathy; 22 had left ventricular hypertrophy; and 11 also had coronary heart disease. Because of significant differences with aging normally, and differences in ages of these subgroups, responses were compared with those of normotensive persons matched for age and sex. With only elevated blood pressure there was no impairment of exercise performance and no increase in S-T segment depression. With ventricular hypertrophy and particularly with retinopathy, maximal exercise duration was shortened. Prevalence of postexertional myocardial ischemia, manifested by S-T segment depression, was increased threefold in those with hypertrophy of the left ventricle. Even greater impairment of exercise duration, maximal heart rate, and systolic pressure was observed in patients with coronary heart disease and hypertension. Prevalence of S-T segment depression was sevenfold greater. This ECG manifestation of myocardial ischemia may represent either an augmented contractile force or a significantly restricted coronary blood supply to limit myocardial perfusion. Differences in duration of exercise and circulatory responses, particularly the product of maximal heart rate and maximal systolic pressure/100, indicate these variations in pathophysiological mechanisms.