Objective
The purpose of this study was to evaluate the beta blocker effect on excercise ability and hemodynamics after cardiac rehabilitation program (CRP).Method: Thirty-two patients with coronary artery disease were divided into two groups: 16 patients in the beta blocker group and 16 patients in the control group. CRP with aerobic exercise was done for 6 weeks. Before and after CRP, a symptom limited graded exercise test was done.Results: The maximal exercise time and the maximal oxygen uptake were significantly higher, and the percentage of maximal oxygen uptake and the rating of perceived exertion were significantly lower after CRP as compared to those parameters before CRP in both groups (p＜0.05). There were no significant differences in above parameters between the beta blocker and control groups (p＞0.05). The submaximal heart rate and submaximal rate pressure product (RPP) were significantly lower after CRP as compared to those before CRP in both groups (p＜0.05). After CRP, the maximal heart rate and the submaximal RPP were significantly lower in the beta blocker group than in control (p＜0.05).Conclusion: A beta blocker can be widely used in CRP without having a negative effect on exercise capacity in the patients with coronary artery disease. (J Korean Acad Rehab Med 2004; 28: 281-287)

Objective
To investigate the safety of exercise program under medical supervision for cardiac patients in their early phase from cardiac events, and the types and the frequency of possible cardiovascular complications during or after exercise. Method: 197 cardiac patients who participated in phase 2 cardiac rehabilitation were selected and they performed aerobic exercise program by individualized exercise prescription under ECG monitoring 3 times a week for 6 weeks. Throughout total 2,429 sessions of exercise, abnormal symptoms, hemodynamic responses and ECG abnormalities were analyzed. Results: Cardiovascular complications ocurred in 25 patients (12.7%). ECG abnormalities in 14 sessions (0.58%) of 13 patients, chest pain during exercise in 17 sessions (0.67%) of 13 patients, abnormal hemodynamic responses in 8 sessions (0.33%) of 8 patients were observed. Cardiac arrest and myocardial infarct didn't happened. 18 patients (72%) experienced these complications during warming-up period, 6 patients (24%) during cool-down period and one patient (4%) during resting period. Conclusion: During exercise, there was some possibility of abnormal ECG changes, chest pain, hemodynamic responses but these potentially dangerous situations could be prevented from advancing on real emergency by intense attention and monitoring. Even cardiac patients of acute stage can tolerate adequate amount of exercise load safely under careful clinical supervision. (J Korean Acad Rehab Med 2002; 26: 797-801)