Short-term responses to cardiac rehabilitation after acute myocardial infarction. Cardiac function evaluation before and after physical training at rest and during stress test.

Whether physical training, soon after myocardial infarction (MI), has effects upon intrinsic cardiac function at rest and during exertion remains unresolved. We have evaluated ventricular function using radionuclide angiography at rest and during stress testing before and after 3 months' physical training. This has been correlated with the site of MI and with changes in the ST segment during the maximal exercise test performed before the postmyocardial infarction rehabilitation program. We have studied 27 patients, mean age 54 +/- 10 years, in NYHA class I or II. Twelve showed no changes in the ST segment during erogmetric stress test (group 1); seven showed ST segment depression greater than 1 mm in leads different from those of MI (group 2); eight showed ST segment elevation of 2 mm (group 3). Twelve patients had had anterior MI only (AMI group); twelve inferior MI only (IMI group). After rehabilitation, all patients showed an increased work capacity and a decreased double product at the same work load. In the total group, significant increases were found in the left ventricular ejection fraction (LVEF) and in the contractile regional performance (LVwm) at rest, as well as a lesser decrease in the LVEF during handgrip test. Group 1 showed a significant increase in LVEF, associated with a decrease in left ventricular end-diastolic volume (EDV) at rest. Group 2 showed unchanged variables after rehabilitation. Group 3 showed a better LVEF during handgrip with an increase of EDV at rest. The AMI group showed a better LVEF and LVwm at rest and a better LVEF during handgrip. IMI group showed a better right ventricular ejection fraction during handgrip without improvement in LVEF. No patient with IMI had septal asynergy. We conclude that the effects of rehabilitation were linked to the site of MI and to the functional dynamic status of both ventricles.