Effects of cardiac rehabilitation on atrial wave in patients after myocardial infarction

Cardiac rehabilitation (CR) can improve cardiac hemodynamic performance in patients after myocardial infarction (MI). Little evidence is provided concerning the consequences of CR on atrial wave duration, and less is known about the link between pre-arrhythmogenic patterns and the cardiovascular performance improvement in these subjects. Twenty-six patients, post-MI 0 to 7 days, underwent a complete CR cycle and a signal-averaged electrocardiogram (SAECG) for the evaluation of atrial activation parameters (group 1) to appreciate if physical training can promote parallel improvement in cardiovascular and intra-atrial conduction parameters. A control group of 24 well-matched nonischemic subjects (group 2) was chosen for data comparison. Resting heart rate (P <0.01) and resting double product (p <0.01) decreased after CR in groups 1 and 2, while diastolic blood pressure at maximal stress was decreased in group I (p <0.01) with a parallel increase in the time of physical training (p <0.05). SAECG parameters of atrial activation were unchanged in group I after the comparison and only total atrial duration activation (dA) reached statistical significance (113.3 +/- 17.2 msec vs 120.8 +/- 14.2 msec, subjects after CR vs before CR, p <0.01). CR could improve intra-atrial activation in subjects after Ml, but the consequences of hemodynamic adjustment of the trained heart must undergo a more accurate evaluation to verify if CR can prevent adverse arrhythmogenic complications of MI through cardiovascular performance improvement.