RÉSUMÉ
Myocardial infarction is a major cause of mortality worldwide. Physical exercise appears to reduce complicationsassociated with myocardial infarction by contributing to cardiac remodeling. The aim of this study was toinvestigate the relation between cardiac remodeling and short-term physical activity. We segregated 9 maleWistar rats into 3 groups: non-operated control, sham-operated (subjected to open chest surgery), and operated(subjected to open chest surgery and ligation of the left anterior descending coronary artery). Operatedand sham-operated animals were enrolled in a physical activity program shortly after surgical recovery. Nonoperatedcontrol rats did not receive physical activity stimulation. The heart size and heart wet weight/body weight ratio in operated rats significantly increased compared with that in control or sham-operatedrats. Moreover, operated rats showed histological evidence of myocardial cell swelling and disorganizationof myocyte architecture. These changes were not observed in control or sham-operated rats. Performingshort-term physical activity at the acute phase of myocardial injury does not mitigate the effects of myocardialinfarction, as evidenced by increased heart size and altered histological features. Longer training sessionsmight be required for obtaining any benefit.