Since the 1980s, early ambulation and cardiac rehabilitation have been emphasized in clincal practice after myocardial infarction. This is based on the belief that cardiac rehabilitation can reduce cardiovascular mortality, improve functional capacity and reduce the risk of further coronary events. In this study, we investigate the effect of aerobic exercise-based cardiac rehabilitation on functiona capacity and cardiopulmonary response in patiets with myocardial infarction.

19 patients were divided into two group(9 patients for training group and 10 patients for control group) at 4-6 weeks after acute myocardial infarction. Training group performed aerobic exercise for 8 weeks(3 sessions per week, mean 53mins per session) at 40-60% of heart rate(HR) reserve, while control group did not. Before and after 8 weeks, all patients performed symptom-limited exercise test using modified Bruce protocol. Also, breath by breath respiratory gas analysis was carried out throughout exercise test.

For body composition, body weight(-2.7%, p<0.001), body mass index(-2.5%, p<0.001) and %body fat(-2.6%, p<0.05) were decrease significantly in training group after 8 week cardiac rehabilitation. Resting HR(-13%, p<0.05) was reduced significantly in training group, but no significant change occured in resting blood pressure between the two groups. Maximal oxygen uptake(18%, p<0.01) and anaerobic threshold(21%, p<0.05) were increased significantly in training group after 8 week cardiac rehabilitation as compared with the control group. There was no significant change in maximal O(2)pulse between the two groups. Submaximal rate-pressure product(-17%, p<0.05) and submaximal rate of perceived exertion (-2.6, p<0.001) were decreased significantly in training group after 8 week cardiac rehabilitation as compared with the control group.

Our findings indicate that cardiac rehabilitation results in the significant improvement of functional capacity and cardiopulmonary response in patients with myocardial infarction. Cardiac rehabilitation for patients with myocardial infarction can contribute early return and readaptation to normal life, because myocardial oxygen consumption(or rate-pressure product) is decreased at the same exercise level after exercise training.