People with chronic heart failure can benefit from a combination of exercise and a dietary supplement known as L-arginine. The combination appears to help correct the abnormal functioning of blood vessels seen in chronic heart failure (CHF), a condition characterized by an enlarged heart that pumps blood inefficiently, resulting in breathlessness and fluid accumulation in the limbs and lungs.

People with heart failure often have blood vessels that fail to dilate in response to certain drugs -- a sign that the inner blood vessel wall, or endothelium, is malfunctioning. In a new study, researchers assigned 40 heart failure patients to one of four treatment groups. The patients either continued their usual treatment, took L-arginine, performed forearm exercises, or performed the exercises in conjunction with L-arginine treatment.

Patients treated with L-arginine had a fourfold increase in blood vessel dilation -- from 2.2% to 8.8%. Regular forearm exercises increased the dilation response by the same amount. However, the combination of L-arginine and exercise training resulted in an even greater response, with an improvement from 2.9% to 12.0%. The study is the first clinical trial to show that exercise and taking L-arginine improves blood vessel dilation more than either factor along. The results suggest that the combined treatment may improve blood vessel functioning in patients with chronic heart failure and, thereby, enhance their exercise capacity beyond what can be done by improving their heart function alone.

Journal of the American College of Cardiology March 2000;35:706-713