title: Endothelium-dependent vasodilation of peripheral conduit arteries in patients with heart failure.
abstract: Endothelium-dependent vasodilation of peripheral resistance vessels is abnormal in patients with heart failure, but there are little in vivo data on endothelium-dependent vasodilation of peripheral conduit vessels. This study assessed endothelium-dependent vasodilation of forearm conduit and resistance vessels in normal subjects and patients with heart failure. The effects of intraarterial endothelium-dependent and endothelium-independent vasodilators on both forearm conduit (brachial artery) and resistance vessels were assessed in 9 patients with New York Heart Association class II-III heart failure and 11 normal subjects of similar age. Brachial artery diameter was measured by two-dimensional, moderate-frequency (8 MHz) ultrasound, and forearm blood flow was measured by strain gauge plethysmography. The endothelium-dependent vasodilator, methacholine (0.3 and 1.5 micrograms/min), increased brachial artery diameter by 7.6 +/- 1.3% and 12.2 +/- 1.5% in normal subjects as compared to 6.9 +/- 2.1% and 10.4 +/- 2.4% in patients with heart failure (P = NS, normal vs heart failure). The endothelium-independent vasodilator, nitroglycerin (0.15 microgram), also produced similar increases in brachial artery diameter in the two groups (8.2 +/- 1.3% in normal subjects vs 11.1 +/- 1.4% in patients with heart failure, P = NS). In contrast, forearm blood flow responses to methacholine were significantly (P < .05) greater in normal subjects (4.1 +/- 0.5 and 9.2 +/- 1.4 mL/min/100 mL forearm volume) than in patients with heart failure (2.0 +/- 0.8 and 5.1 +/- 1.3 mL/min/100 mL forearm volume). Forearm blood flow responses to the endothelium-independent vasodilator, sodium nitroprusside, were similar between the two groups. This study suggests that endothelium-dependent and endothelium-independent vasodilation of the brachial artery is not impaired in patients with class II-III heart failure. This finding contrasts with abnormal endothelium-dependent vasodilation of forearm resistance vessels. These data suggest that there are regional differences in endothelial function in patients with heart failure.
authors.affiliation: Department of Medicine, University of Minnesota Medical School, Mineapolis 55455, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Bank
authors.forename: T S
authors.initials: TS
authors.lastname: Rector
authors.forename: L K
authors.initials: LK
authors.lastname: Tschumperlin
authors.forename: M D
authors.initials: MD
authors.lastname: Kraemer
authors.forename: J G
authors.initials: JG
authors.lastname: Letourneau
authors.forename: S H
authors.initials: SH
authors.lastname: Kubo
mesh_terms: D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005542:Forearm / Q000098:blood supply; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014664:Vasodilation / Q000502:physiology*