J-wave duration and slope as potential tools to discriminate between benign and malignant early repolarization

Abstract

Interest in early repolarization (ER) increased after the theoretical proposal1 and the clinical demonstration2 that certain electrocardiographic (ECG) patterns characterized by an elevation of the J point were associated with an increased risk of sudden cardiac death in otherwise healthy individuals. Previous studies showed that only the rare pattern characterized by a significant J-point elevation (≥2 mm) in the inferior leads associated with a slurred J wave and a horizontal/descending ST segment was associated with an increased risk of death (whether arrhythmic, from cardiac or any cause).3, 4, 5 and 6 Whether this pattern may constitute a real primary arrhythmic disorder rather than a predisposing substrate facilitating arrhythmias during ischemic episodes is still a matter of debate.
Moreover, those findings are somehow in contrast with the clinical evidence of patients presenting with idiopathic ventricular fibrillation and several different morphologies of the J wave and ST segment, questioning what is the real ECG marker able to distinguish between a malignant and a benign form of ER.
Thus, the aims of the present study were to compare the amplitude of J waves by measuring slope and duration in patients with ER syndrome and healthy athletes with ECG evidence of J-point elevation associated with J wave and to evaluate its potential role as an ECG marker of increased arrhythmic risk.