The ECG pattern of early repolarization has historically been regarded as a benign ECG variant, but during the past few years, this concept has been challenged based on multiple reports linking the ER pattern with an increased risk of sudden cardiac death.

Young male with occasional atypical chest pain. (The ECG borrowed from Dr. Yasin Rasa from Kabul)

Malignant vs. benign patterns of ER

There are 3 criteria which raise arrhythmia risk in early repolarization;
1- ST elevation in inferior leads
2- J-wave elevation >2 mm
3- Horizontal ST elevation
(J.T. Tikkanen, H.V. Huikuri. Characteristics of malignant vs benign electrocardiographic patterns of early repolarization. J Electrocardiol 2015)

Horizontal ST elevation

• There has not been a standardized definition of ER, and the authors of this document recommend that the term "early repolarization pattern" (ERP) be used to refer either to ST-segment elevation in the absence of chest pain, terminal QRS slur, or terminal QRS notch.
• Early repolarization syndrome (ERS) refers to patients with ERP who have survived idiopathic ventricular fibrillation.
• Because the risk of VF in an asymptomatic young adult with ER is estimated to be only 1/3,000 even when the ST segment is horizontal, the ST segment morphology is not useful for clinical decision making unless the individual has had loss of consciousness compatible with cardiac syncope.
• Evaluation of asymptomatic individuals with ERP is not recommended.
(Patton KK, Ellinor PT, Ezekowitz M, et al. Electrocardiographic Early Repolarization: A Scientific Statement From the American Heart Association. Circulation 2016;Mar 7)