The effect of salbutamol on skeletal muscle in chronic heart failure

We performed a randomised placebo-controlled trial to investigate the effec ts of the anabolic drug salbutamol on skeletal muscle and exercise capacity in chronic heart failure. Twelve patients received salbutamol slow-release 8 mg twice daily or placebo for 3 weeks. We assessed the effect of treatme nt on exercise capacity, quadriceps muscle bulk, maximal isometric strength and fatigue, respiratory muscle strength, spirometry and 24-h ECG (electro cardiogram). There was no significant change in the muscle indices, exercis e time or peak oxygen consumption. The frequency of ventricular arrhythmias and spirometric measurements were also unchanged. Maximal expiratory mouth pressure, measured at total lung capacity and functional residual capacity , increased significantly (+29.7+/-10.6 vs. -0.5+/-7.5 cm H2O [mean+/-S.E.M ., change over 3 weeks treatment salbutamol vs. placebo] and +31.2+/-5.4 vs . +0.2+/-4.0 cm H2O both P<0.05). Maximal inspiratory pressures showed a tr end towards increasing with treatment when measured from either lung volume (-22.8+/-9.5 vs. -6.2+/-3.6 cm H2O, P=0.14 and -21.5+/-7.5 vs. -3.5+/-3.4 cm H2O, P=0.054). Treatment with 3 weeks of salbutamol increases respirator y muscle strength in chronic heart failure but does not improve quadriceps abnormalities or exercise capacity. Salbutamol is unlikely to have a role i n treating the muscle abnormalities in chronic heart failure. (C) 2000 Else vier Science Ireland Ltd. All rights reserved.