Attenuated endothelium-dependent peripheral vasodilation and clinical characteristics in patients with chronic heart...

Impairment of endothelium-dependent vasodilation has recently been reported in the peripheral vascular bed in patients with chronic heart failure. However, the clinical implications of this type of vascular dysfunction have yet to be elucidated. We have determined the degree of impairment of endothelium-dependent vasodilation as evaluated by acetylcholine-induced changes in forearm blood flow and compared this to various clinical parameters in 23 patients with chronic heart failure. Cumulative changes in forearm blood flow induced by acetylcholine (3.0 and 4.5 micrograms/min/dl tissue volume) were significantly lower in patients with chronic heart failure than in normal controls (10.1 +/- 8.0 ml/min/100 ml vs 20.4 +/- 11.7 ml/min/100 ml tissue volume; p < 0.01). In patients with heart failure, no significant relation was found between acetylcholine-induced changes in forearm blood flow and age, sex, duration of symptoms, duration of hospital stay, or resting hemodynamic parameters, although a significant positive correlation was observed with peak oxygen uptake (r = 0.53, p < 0.05) and ventilatory threshold (r = 0.42, p < 0.05). These observations suggest that the impairment of endothelium-dependent peripheral vasodilation may be one of the factors contributing to exercise intolerance in patients with chronic heart failure, probably resulting from its limiting effect on nutritive skeletal muscle blood flow during exercise.