High- intensity interval training improved left ventricular function in post myocardial infarction rats

Myocardial infarction (MI) is one of the most important ischemic cardiopathy which causes of mortality and morbidity throughout worldwide. Myocardial remodeling Following MI is associated with decreased contractile function and impairment to systolic and diastolic functions of the left ventricle. Generally, it is accepted that exercise training improves cardiac function after MI. The aim of this study was to investigation the effect of high- intensity interval training (HIIT) on structural and functional in post- MI rats. Methods and materials:

Adult male Wistar rats (n = 32) were randomly divided into 4 groups of ischemia/ reperfusion control (MI-CTL), ischemia/reperfusion HIIT exercise (MI-HIIT), HIIT exercises/healthy rats (HIIT) and SHAM-operated groups. MI modeling was induced by the left anterior descending coronary artery (LAD) ligation. HIIT training started 4 weeks after LAD ligation. Rats ran on treadmill 40 min, 3 days a week for 8 weeks.

The results showed that, there was a significance increase in exercise capacity and cardiac function indices (ejection fraction and fractional shortening) in MI-HIIT group compared to MI-CTL group (p < 0.05). HIIT significantly decreased ventricular dilation and infarct size in comparison with MI-CTL group (p < 0.05). While, there were no significant difference in serum level of cTnI, CK-MB in among groups.

HIIT led to improvement in ventricular contractile function and decrease in pathologic remodeling following MI.