Exercise training for patients with coronary artery disease. Cardiac rehabilitation revisited

Medically prescribed and supervised physical activity forms the keystone for cardiac rehabilitation. A patient's potential and limitations for successful participation in an active restoration programme are determined by the degree of symptomatic recovery and physiological adaptations to a standardised, multistage exercise test. Confirmation of the effects of physical activity intervention is measured by the performance of the same exercise test under near identical conditions at periodic intervals. The prescribed physical activity regimen is usually performed minimally 3 times per week in sessions which last from 30 to 60 minutes. The object is to utilise from 100 to 200 kcal per exercise session. The demonstrated benefits of regular physical activity include reduction of the systolic blood pressure and heart rate at supine rest and while performing submaximal work, an increased level of physical work capacity, reduction in the myocardial oxygen cost at rest and during performance of submaximal exercise, reduction in percentage body fat with a concomitant increase in muscle mass, and reduction in plasma triglycerides. Regular physical activity, in and of itself, does not effect a reduction in plasma cholesterol or an increase in high density lipoprotein cholesterol, nor does it affect such lifestyle habits as cigarette smoking and alcohol consumption. While contraindications to performing medically prescribed and supervised physical activity are usually restricted to the physically incapacitated patient, failure to achieve an exercise threshold for systolic blood pressure of 140mm Hg or higher is probably a contraindication. This conclusion is based on findings which indicate that treated and control patients with this physiological limitation experience the same mortality rates over 3 years. Regularly performed physical activity by coronary artery diseased patients is associated with reductions in mortality from all cardiovascular causes except sudden death. This intervention does not effect morbidity. Although the scientific evidence warrants the prudent use of physical activity for coronary artery disease patients, the case for its long term benefits remains to be proved.