Endothelium-dependent forearm vasodilation to acetylcholine but not to substance P is impaired in patients with heart failure.

It has been shown that endothelium-dependent vasorelaxation in response to muscarinic stimulation is attenuated in patients as well as animals with heart failure. This study aimed to determine if endothelium-dependent forearm vasodilation evoked with substance P (SP) as well as acetylcholine (ACh) was impaired in patients with heart failure. Forearm blood flow was measured using a strain-gauge plethysmograph and forearm vascular responses to intra-arterial infusions of ACh, SP, or sodium nitroprusside (SNP) at graded doses were examined