Regular physical exercise corrects endothelial dysfunction and improves exercise capacity in patients with chronic heart failure

Background-The purpose of this study was to determine the effects of system ic exercise training on endothelium-mediated arteriolar vasodilation of the lower limb and its relation to exercise capacity in chronic heart failure (CHF). Endothelial dysfunction is a key feature of CHF, contributing to inc reased peripheral vasoconstriction and impaired exercise capacity. Local ha ndgrip exercise has previously been shown to enhance endothelium-dependent vasodilation in conduit and resistance vessels in CHF. Methods and Results-Twenty patients were prospectively randomized to a trai ning group (n = 10, left ventricular ejection fraction [LVEF] 24+/-4%) or a control group (n=10, LVEF 23+/-3%). At baseline and after 6 months, peak f low velocity was measured in the left femoral artery using a Doppler wire; vessel diameter was determined by quantitative angiography. Peripheral bloo d flow was calculated from average peak velocity (APV) and arterial cross-s ectional area. After exercise training, nitroglycerin-induced endothelium-i ndependent vasodilation remained unaltered (271% versus 281%, P=NS). Periph eral blood flow improved significantly in response to 90 mu g/min acetylcho line by 203% (from 152+/-79 to 461+/-104 mL/min, P<0.05 versus control grou p) and the inhibiting effect of L-NMMA increased by 174% (from -46+/-25 to -126+/-19 mL/min, P<0.05 versus control group). Peak oxygen uptake increase d by 26% (P<0.01 versus control group). The increase in peak oxygen uptake was correlated with the endothelium-dependent change in peripheral blood fl ow (r=0.64, P<0.005). Conclusions-Regular physical exercise improves both basal endothelial nitri c oxide (NO) formation and agonist-mediated endothelium-dependent vasodilat ion of the skeletal muscle vasculature in patients with CHF. The correction of endothelium dysfunction is associated with a significant increase in ex ercise capacity.