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| |  Exercise Improves Heart Health For Those With Chronic Heart Failure CHICAGO, IL -- June 20, 2000 -- Exercise can help patients with chronic heart failure improve their circulation, increase the amount of blood pumped by the heart with each beat and reduce heart enlargement, according to an article appearing in the June 21 issue of The Journal of the American Medical Association (JAMA). Rainer Hambrecht, M.D., and colleagues from Universitat Leipzig, Leipzig, Germany, randomly assigned 73 men aged 70 years or younger (average age, 54 years) with chronic heart failure to an exercise program (n = 36) or to no intervention (control group = 37) to evaluate the effects of exercise training on left ventricular function and blood circulation in patients with stable chronic heart failure. Left ventricular function is important because blood circulation within the body begins with the left ventricle pumping blood out of the heart and into the arteries. The exercise patients used a bicycle ergometer to maintain a specific, consistent exercise level of 70 percent of peak oxygen uptake. The first two weeks of in-hospital exercise lasted 10 minutes, four to six times a day, and was followed by six months of home-based bicycle ergometer exercise training for 20 minutes per day. The authors performed echocardiograms and heart catheterization for all patients at the beginning and end of the study to measure heart size and heart function. "After six months, patients in the exercise training group had statistically significant improvements compared with controls in New York Heart Association functional class, maximal ventilation, exercise time and exercise capacity as well as decreased resting heart rate and increased stroke volume [volume of blood pumped by the heart with each beat] at rest," the researchers explain. The researchers found that as stroke volume improved, those in the exercise group had significant enhancements in maximum heart output during exercise. According to background information in the article, strenuous physical activity generally has not been recommended for patients with chronic heart failure who demonstrated an intolerance to exercise. However, during the last decade it has become appreciated that this approach accelerates physical deconditioning and may worsen heart failure symptoms. The researchers report three key findings: "First, aerobic endurance training leads to an increase in left ventricular stroke volume at rest and during exercise and to a small but significant decrease in left ventricular end diastolic diameter and volume. ... Second, long-term exercise training is associated with a considerable reduction of [total peripheral resistance {peripheral resistance is opposition to blood flow due to pressure in the arteries}] at rest and, in particular, at peak exercise. ... Third, changes in [total peripheral resistance] are related to changes in stroke volume and left ventricular end diastolic diameter." "Home-based exercise training in patients with chronic heart failure results in a considerable reduction of [total peripheral resistance], a small but significant improvement in [left ventricular] stroke volume and reduction in cardiomegaly [heart enlargement]," conclude the authors. "Although several questions regarding optimal training protocol and training intensity remain unanswered, the present findings may have important implications for rehabilitation of patients with chronic heart failure." Related Link: The Journal of the American Medical Association (JAMA).
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