Different response of patients with idiopathic and ischaemic dilated cardiomyopathy to exercise training

We looked at the benefits and complications of a home-based exercise programme in patients with ischaemic and idiopathic dilated cardiomyopathy. Twenty-four patients with left ventricular end-diastolic dimension >6.5 cm and fractional shortening <25% entered a cross-over trial of 8 weeks training versus 8 weeks rest. Echocardiography, electrocardiogram and cardiopulmonary exercise testing were performed at baseline, after training and after detraining. Training resulted in a higher peak oxygen consumption (26.5 versus 21.3 ml/kg/min, P=0.004), a higher peak heart rate (161 versus 152 bpm, P=0.02) and improved well-being. Patients with idiopathic dilated cardiomyopathy showed a significant increase in exercise time (879 versus 828 s, P=0.03) and peak oxygen consumption (31.3 versus 24.3 ml/kg/min, P=0.02) and a decrease in left ventricular end-diastolic dimension (6.4 versus 6.9 cm, P=0.01) and end-systolic dimension (5.3 versus 5.8 cm, P=0.04) in contrast to those with coronary artery disease, who developed a reduction in septal excursion and shortening rate following training. Complications of training were more common in those patients with ischaemic cardiomyopathy, greater left ventricular dimensions, poorer exercise tolerance and greater ventilation drive at baseline, and included fluid retention and exercise-induced ventricular tachycardia. We found that this group of patients with a dilated, poorly functioning left ventricle can safely derive benefit from a home-based exercise programme, particularly those of idiopathic origin, but they should be closely monitored for the development of complications.