Early repolarization and markers of ventricular arrhythmogenesis in patients referred to ambulatory 24-hour ECG recording

Abstract

Background: Recent reports suggest that early repolarization, a common electrocardiographic (ECG) pattern that has been always considered benign, could be a substrate for ventricular arrhythmias and sudden cardiac arrest.

Methods: We examined the associations between early repolarization and markers of ventricular arrhythmogenesis as defined by presence of ventricular late potentials (LPs) in the Signal Averaged ECG (SA-ECG), depressed heart rate variability (HRV) and/or presence of ventricular ectopy in patients referred to ambulatory 24-hour ECG recording (Holter).

Results: This study included 687 patients (57% females) who were 51.2 ± 5.1 years. In unadjusted and multivariable adjusted analyses, early repolarization was not significantly associated with any of the measures of SA-ECG, HRV or ventricular ectopy. The lack of significant associations persisted in all subgroup analyses where different definitions of early repolarization in different groups of ECG leads were tested.

Conclusions: Early repolarization has no significant association with markers of ventricular arrhythmogenesis as detected by SA-ECG, HRV and ventricular ectopy. These findings suggest that the mechanisms of arrhythmic events in early repolarization (if they truly exist), are not likely to be through pathological pathways that could be detected by these markers.