Effects of Captopril on Forearm Oxygen Consumption during Dynamic Handgrip Exercise in Patients with Congestive Heart Failure

The maximal exercise capacity of patients with congestive heart failure (CHF) is frequently decreased because of decreased skeletal muscle oxygen utilization. In this study we examined whether forearm oxygen utilization is decreased during dynamic handgrip exercise in patients with CHF and whether captopril improves forearm oxygen utilization. They were divided into 3 groups according to the level of plasma renin activity (PRA) and New York Heart Association functional classification (NYHA): Group 1 consisted of 7 normal (control) subjects (PRA: 0.5±0.2ng/ml/h, NYHA: 0); Group 2, 7 patients with severe CHF (PRA: 11.3±3.9ng/ml/h, NYHA: 3.6±0.3); Group 3, 4 patients with mild CHF (PRA: 2.4±0.2ng/ml/h, NYHA: 2±0). Forearm blood flow was measured by a strain gauge plethysmograph at rest and during dynamic handgrip exercise. Regional arterial venous oxygen content was measured and forearm oxygen consumption was calculated by the Fick principle. Forearm blood flow was less (p