IMPAIRED CHOLINERGIC PERIPHERAL VASODILATION AND ITS RELATIONSHIP TO HYPEREMIC CALF BLOOD-FLOW RESPONSE AND EXERCISE INTOLERANCE IN PATIENTS WITH CHRONIC HEART-FAILURE

This study examined the peripheral endothelium-dependent vasodilatory response to acetylcholine and the endothelium-independent vasodilatory response to nitroprusside in 19 patients with chronic heart failure a nd eight controls. These peripheral blood flow responses were compared with hyperemic calf blood flow changes after maximum leg exercise and 5-min femoral occlusion. The peripheral blood flow response to forear m intra-arterial infusion of acetylcholine and sodium nitroprusside, a nd reactive hyperemic calf blood flow changes were measured by plethys mography. All peripheral blood flow responses were significantly reduc ed in patients with chronic heart failure (P < 0.05). Reduction of ace tylcholine-mediated changes in peripheral blood flow was correlated wi th exercise-induced calf blood flow response (r = 0.51, P < 0.05), but not with occlusion-induced calf blood flow response (r = 0.02, NS). S odium nitroprusside-mediated changes were not correlated with any reac tive hyperemic blood flow responses (exercise: r = 0.27, NS; occlusion : r = 0.11, NS). When the patients were divided into two subgroups bas ed on the median exercise-induced calf blood flow change, the subgroup with the lower calf blood flow response showed a reduction in exercis e capacity (anaerobic threshold: 11.8 +/- 0.6 vs. 14.6 +/- 1.0 ml/kg/m in; P < 0.05). These findings suggest that endothelial dysfunction is related to a decrease in exercise-induced skeletal muscle blood flow a nd exercise capacity in patients with chronic heart failure.