Effects of Physical Training in Dogs with Coronary Artery Ligation

This experiment was designed to determine whether physical conditioning can be achieved in the presence of acute myocardial infarction and whether such an exercise program is harmful. For this purpose the effects of a 5-weeks' treadmill-exercise program and inactivity were compared in two groups of dogs in which acute myocardial infarction was produced by coronary artery ligation. The exercised group of animals tolerated the training program well, and neither arrhythmia nor sudden death occurred. At the end of the training program the exercised group of animals displayed the characteristic changes of physical conditioning, namely, reduction in exercise heart rate, cardiac output, and blood lactate levels; rise in circulating epinephrine levels with exercise was also suppressed by conditioning. Postmortem examination revealed neither ventricular dilatation nor aneurysm formation.