Table 1. The difference between traditional and modern ER.

	Traditional ER definition	Modern ER definition
Time of firstly proposed	1961	2008
Major difference in diagnosis	Upwardly concave ST segment Elevation	An elevation of the QRS–ST junction
Mechanisms	AP plateau depression in the epicardium related to Ito-mediated AP notch	Ito-mediated AP notch and IVCD
12 lead ECG recognition	ER can be easily identified in 12 lead ECG	ER can be often confused with IVCD in 12 lead ECG
Risk for VF	Rare, considering benign	Depending on J wave amplitude and related changes in ST and T wave
Prevalence	lower	higher

ER: early repolarization, AP: action potential, ECG: electrocardiography, VF: ventricular fibrillation, IVCD: intraventricular conduction delay