Heart failure and afterload reduction using exercise: In a prospective randomized trial, the authors evaluated the effects of 6 months of exercise training in patients with stable chronic heart failure and moderate-to-severe left ventricular (LV) dysfunction in 73 men aged 70 years or younger. Patients were randomly assigned to 2 weeks of in-hospital ergometer exercise for 10 minutes 4 to 6 times per day, followed by 6 months of home-based ergometer exercise training for 20 minutes per day at 70% of peak oxygen uptake (n=36) or to no intervention (control group; n=37). Results indicated that aerobic endurance training leads to an increase in LV stroke volume at rest and during exercise and to a small but significant decrease in LV end diastolic diameter and volume. Cardiac output at rest and during sub-peak exercise remains almost unchanged. Long-term exercise training is associated with a reduction of total peripheral resistance (TPR) in the exercise training group vs an increase in the control group, p=0.003). Total peripheral resistance (TPR) is the amount of resistance to blood flow present in the vascular system of the body. These results suggest that in patients with stable chronic heart failure, regular physical exercise for 6 months is associated with a significant afterload reduction. This beneficial training effect leads to a small but significant improvement in LV stroke volume and reduction in cardiomegaly, enlargement of the heart seen in heart failure. (16)
