Influence of prior exercise on stroke volume to pulse pressure ratio in young subjects with hypertension or dilated cardiomyopathy

Abstract

The objectives of this study were, first, to compare stroke volume to brachial artery pulse pressure ratios (SV/PP) as noninvasive, indirect estimates of total arterial compliance, in young subjects with primary hypertension or dilated cardiomyopathy and age-matched normal subjects and, second, to determine the influence of prior submaximal exercise on this ratio, and on calf and total peripheral vascular conductance in these subjects. We studied young patients (< 40 years old) with primary hypertension (n = 12) or dilated cardiomyopathy (n = 12) and healthy normotensive subjects (n = 12) matched for age and body size. Doppler estimated stroke volume, brachial artery pulse pressure, and calf blood flow were determined during supine rest before and 60 min after exercise. Normotensive and hypertensive subjects returned 1 month later to determine the reproducibility of the SV/PP value. At rest, the SV/PP value was inversely related to left ventricular mass index (r = -0.55, p < 0.001) and was similar in normotensive and hypertensive subjects, but was significantly lower (p < 0.05) in cardiomyopathy. The SV/PP value was reduced 60 min after exercise in both normotensive (p < 0.05) and hypertensive (p < 0.05) subjects, but not in cardiomyopathy patients. In contrast, total and calf vascular conductance increased after exercise in all three groups. These aftereffects indicate that these estimates of compliance and conductance are dynamic, and can be modulated acutely and independently by exercise.