DOES APPROPRIATE ENDURANCE EXERCISE TRAINING IMPROVE CARDIAC-FUNCTIONIN PATIENTS WITH PRIOR MYOCARDIAL-INFARCTION

Objective The objective of the present study was to determine whether appropriate endurance exercise training improves cardiac function in p atients with prior myocardial infarction. Methods Twenty-nine patients with prior myocardial infarction were divided into three groups (Grou p 1: control, Group 2: low-intensity training, Group 3: high-intensity training). Low and high training intensities were determined accordin g to the gas exchange threshold of each patient. The patients in Group s 2 and 3 performed 15 min of home-based physical training safely, twi ce a day, 5 days a week for 2 months. Prior to and following this trai ning, each patient performed two constant work rate tests (moderate an d heavy intensity) and a symptom-limited incremental exercise test. Re sults Heart rates at rest and during exercise were decreased significa ntly after 2 months in all three groups. Stroke volume at rest increas ed significantly after only in Group 3. Stroke volume after 6 min of h eavy-intensity exercise increased significantly in Groups 2 and 3. How ever, the ejection fraction at 6 min of heavy-intensity exercise incre ased significantly only in Group 3. The maximal work rate attained dur ing incremental exercise testing increased significantly in Groups 2 a nd 3. This parameter did not significantly change in the control group . Conclusions Effects of physical training on maximal exercise capacit y were noted in both exercise training groups. However, improvement in cardiac function (such as stroke volume), both at rest and during exe rcise, was noted only in the high-intensity training group. Our result s suggest that relatively high-intensity training may improve exercise capacity and cardiac function of patients with prior myocardial infar ction.