Acetylcholine-Induced and Ischemic Vasodilation of the Forearm in Patients With Heart Failure

Background Endothelium-dependent vasodilation in response to acetylcholine (ACh) and ischemic vasodilation during reactive hyperemia are attenuated in the forearm of patients with heart failure (HF). It has been shown that L-arginine augments endothelium-dependent vasodilation in healthy subjects. Thus, the aim of the present study was to determine if L-arginine improves endothelium-dependent and ischemic vasodilation in the forearm in HF. Methods and Results Forearm blood flow was measured by a strain-gauge plethysmograph in 20 patients with HF and in 24 age-matched control subjects (C). Resting forearm vascular resistance (FVR) was significantly higher in HF than in C (37±4 versus 22±2 U, P<.01). Intra-arterial infusions of ACh or sodium nitroprusside (SNP) at graded doses progressively decreased FVR in HF as well as in C. The magnitude of