Background: Exercise training improves endothelium-dependent vasodilation in animals. This study was designed to determine whether forearm exercise training improves endothelium-dependent vasodilation in control subjects and patients with heart failure, a disease associated with abnormal endothelium-dependent vasodilation.
Methods and results: We used strain gauge plethysmography to assess the effects of short-term forearm exercise training on resistance vessel function in 11 control subjects and 7 patients with New York Heart Association class II and III heart failure. Subjects performed 30 minutes of handgrip exercise four times a week for 4-6 weeks. In the control subjects, exercise training increased forearm blood flow (FBF) responses to intra-arterial acetylcholine (20 microg/min) from 6.9 +/- 3.1 to 12.2 +/- 3.0 mL/min/100 mL and peak reactive hyperemic FBF responses from 38.1 +/- 5.6 to 47.4 +/- 5.6 (P < .05). Basal FBF and responses to nitroprusside, L-N-monomethyl arginine and acute forearm exercise were not significantly changed. In the patients with heart failure, chronic forearm exercise did not significantly change any of the above-measured parameters.
Conclusion: Forearm exercise training improves endothelium-dependent vasodilation and peak hyperemic FBF in control subjects but not in patients with heart failure. These data suggest that resistance vessel abnormalities may not be as readily modifiable by exercise training in patients with heart failure compared with control subjects.