[Effect of exercise therapy on recovery phase of myocardial infarction: comparison with a control group]

Exercise therapy at the anaerobic threshold (AT) level is currently recommended for patients recovering after myocardial infarction (MI). However, the effects of exercise therapy have not been investigated in a controlled prospective study. This study investigated whether AT-level physical training is beneficial in improving exercise tolerance and left ventricular function during the MI recovery phase in 62 patients who had no contraindications for exercise during hospitalization. Exercise therapy at the AT-level was continued after discharge in 43 patients (group T), and was discontinued in 19 patients (group C). Treadmill exercise testing with a ramp protocol was performed at 1 and 3 months after the onset of MI. AT, peak VO2, and VO2 slope (delta VO2/delta exercise time) were determined. Cardiac catheterization was performed in 48 patients (33 in group T and 15 in group C) 3 months after the onset of MI. Ejection fraction (EF), stroke index (SI), end-diastolic volume index (EDVI), and end-systolic volume index (ESVI) were determined. The following results were obtained; 1) AT, peak VO2, and VO2 slope significantly increased in group T, but not in group C; and 2) EF, SI, EDVI and ESVI were not significantly different between these two groups. Exercise therapy at the AT-level during the MI recovery phase significantly improved exercise tolerance and oxygen uptake, but had no significant influence on left ventricular function.