Figure 1. Percent increase in blood flow (perfusion units) compared to base line (set as 100%) in healthy individuals (n = 10), patients with congestive heart failure of NYHA II (n = 15) and NYHA IV (n = 20). (A) endothelium-dependent responses to acetylcholine; (B) endothelium–independent relaxation response to sodium nitroprusside; (C) general vasodilator response to local heating to +44 °C. Values represent mean maximum relaxation ± SE. NYHA: New York Heart Association classification; ACh: Acetylcholine; SNP: sodium nitroprusside.