To the question of electrophysiological remodeling role in the genesis of ventricular ectopy in patients with postinfarction cardiosclerosis

Aim. To study the character and intensity of relationship between left ventricular dilatation, severity of electrophysiological myocardium remodeling and ectopic ventricular activity in patients with postinfarction cardiosclerosis.

Methods. 46 patients with postinfarction cardiosclerosis were examined (males, average age 57.9 years). All patients underwent echocardiography with detection of end diastolic volume of left ventricle and its ejection fraction, Holter monitoring with determining signal-averaged electrocardiogram and severity of ventricular ectopic activity with calculation of ventricular ectopic activity index. Based on the ejection fraction the patients were divided into two groups. Group 1 included 17 patients with ejection fraction ≥45%, and group 2 - 29 patients with ejection fraction <45%.

Results. Left ventricle ejection fraction in patients from group 2 was lower, and parameters of signal-averaged electrocardiogram were worse than in patients from group 1. Ventricular ectopic activity index in patients from group 2 was 5 times higher than the average index in group 1. According to correlation analysis in the combined group, signal-averaged electrocardiogram parameters more tightly correlated with end diastolic volume than with ventricular ectopic activity index. The latter more tightly correlated with end diastolic volume (r=0.67, p <0.001), than with signal-averaged electrocardiogram parameters. After calculating partial correlation coefficient and excluding the effect of end diastolic volume, correlation coefficients of ventricular ectopic activity index and signal-averaged electrocardiogram parameters became insignificant. The received data put in question the view that electrophysiological remodeling is an independent cause of severity increase of ventricular arrhythmias. More probable is that electrophysiological remodeling and ventricular ectopic activity are related pathogenetically, and correlation between them is determined by the fact that both depend on left ventricle end diastolic volume.

Conclusion. Relation between electrophysiological myocardium remodeling and ectopic ventricular activity in patients with postinfarction cardiosclerosis may depend on severity of left ventricular dilatation.