Peripheral vascular resistance limits exercise functional capacity of mildhypertensives

To evaluate the physiological basis for suboptimal peak exercise oxygen con sumption ((V) over dot O(2)p) observed in the early stage of hypertension, 25 WHO Stage I hypertensive men with normal left ventricular mass and 10 he althy control subjects of equivalent age underwent the maximal cardiopulmon ary exercise test with contemporary measurement of cardiac output with Tc99 m angiocardiography. At peak exercise hypertensive patients had lower (V) o ver dot O(2)p (p < 0.045) and cardiac output (p < 0.014) and higher vascula r resistance (p < 0.010) than controls. At multiple regression analysis (V) over dot O(2)p was positively related to cardiac output in controls (r = 0 .80, p < 0.02), whereas in hypertensives the best (negative) correlation wa s observed with peripheral vascular resistance (r = -0.72, p < 0.04). Thus reduced cardiopulmonary function during physical exercise in hypertensives seems to be mainly related to impaired peripheral vascular autoregulation.