The Early Repolarization ECG Pattern – An Update

Abstract

Early repolarization pattern (ERP), a form of J-wave syndromes, was considered long time a benign ECG phenomenon. However, recent data confirmed that certain phenotypes of ERP are related to an increased risk of sudden cardiac death (idiopathic ventricular fibrillation). Our paper gives a short and practical update regarding the main issues related to ERP: epidemiological data, molecular and electrophysiological background, clinical significance and risk stratification. At the end, the future directions of research and clinical management related to ERP are presented.Keywords: J-wave, early repolarization syndrome, sudden cardiac death Introduction. History From the beginning of electrocardiography, so called idiopathic J-waves were found on the ECG recordings of many species, including humans. The J-point on ECG is defined as the transition between the end of the QRS complex and the ST segment. Deviation of this point from the isoelectric line determine the presence of J-deflection (wave), which could be followed by upsloping or horizontal ST-segment elevation, determining the appearance of early repolarization ECG pattern (ERP). The ERP was first described in 1936 by Shipley and Hallaran, who studied 200 young healthy men and women and described the Jdeflection as notching of the descending part of the QRS complex [1][2][3].ERP was considered previously as a benign, "innocent", ECG phenomenon, as a distinct form of the so called J-wave syndromes (which include also the Brugada syndrome). However, in the last ten years, epidemiological and case-control studies found some forms of ERP to be predictors and risk factors for sudden cardiac death (primary ventricular fibrillation). This is particularly true, when the ST segment has a horizontal or descending direction in the inferior and/or infero-lateral leads. The risk is even higher when the amplitude of J-wave is greater than 0.2 mV [2].

Early repolarization syndrome in modern interpretation

“…It is these approaches to the evaluation of the J-sign that are the most reasonable and recommended for use nowadays [6,7]. The horizontal or descending ST segment is currently considered to be more "malignant" [19].…”