Introduction
The benefit of exercise post-acute myocardial infarction (AMI) has been investigated for several years and the vast majority of publications have demonstrated a better prognosis related to this practice.1-7. Physical activity post-AMI is associated with better clinical evolution, with increased functional capacity and less progression to heart failure, preventing malefic cardiac remodeling.4, 8-10
This benefit has been mainly demonstrated in cases of AMI that result in greater contractile involvement of the LV causing moderate to severe systolic dysfunction (LVEF < 40%).11-18However, with greater dissemination of information regarding the recognition of AMI “alarm symptoms”, greater promptness of care, evolution of the therapies employed, less impairment of cardiac contraction after AMI has become more frequent. So, observation of ischemic cardiomyopathy with preserved LV systolic function or mild dysfunction (LVEF 45% to 55%) is very common nowadays in the general population. Regarding to all this, little is known about the real benefit of exercise on LV remodeling and objective effect on LV mechanics of contraction in this population.
Echocardiogram with speckle tracking technique can perform a comprehensive study of LV contraction mechanics, which is characterized by longitudinal apex-to-base shortening in association to segmental rotations and ventricular torsion. This analysis adds numerous data over a simple determination of LV ejection fraction.19-25
The present study aims to test the hypothesis that cardiovascular rehabilitation under a supervised exercise program, in an uncomplicated post-infarction population, would have a positive impact on the mechanics of LV contraction.