PHYSICAL-TRAINING IMPROVES ENDOTHELIAL FUNCTION IN PATIENTS WITH CHRONIC HEART-FAILURE

Background Chronic heart failure is associated with endothelial dysfun ction including impaired endothelium-mediated, flow-dependent dilation (FDD). Since endothelial function is thought to play an important rol e in coordinating tissue perfusion and modulating arterial compliance, interventions to improve endothelial dysfunction are imperative. Meth ods and Results To assess the potential of physical training to restor e FDD, 12 patients with chronic heart failure were studied and compare d with FDD of 7 age-matched normal subjects. With a recently developed high-resolution ultrasound system, diameters of radial artery were me asured at rest, during reactive hyperemia (with increased flow causing endothelium-mediated dilation), and during sodium nitroprusside, caus ing endothelium-independent dilation, Determination of FDD was repeate d after intra-arterial infusion of N-G-monomethyl-L-arginine (L-NMMA, 7 mu mol/min) to inhibit endothelial synthesis and release of nitric o xide. The protocol was performed at baseline, after 4 weeks of daily h andgrip training, and 6 weeks after cessation of the training program. FDD was impaired in heart failure patients compared with normal subje cts. L-NMMA attenuated FDD, indicating that the endothelial release of nitric oxide is involved in FDD. Physical training restored FDD in pa tients with heart failure. In particular, the portion of FDD inhibited by L-NMMA (representing FDD mediated by nitric oxide) was significant ly higher after physical training (S-minute occlusion: 8.0+/-1% versus 5.4+/-0.9%; P<.05; normal subjects: 9.2+/-1%). Conclusions These resu lts indicate that physical training restores FDD in patients with chro nic heart failure, possibly by enhanced endothelial release of nitric oxide.