Background Recent data showed that early repolarization (ER) could be associated with ventricular fibrillation (VF) and sudden cardiac death. Electrocardiogram (ECG) markers identifying malignant forms of ER from normal variants are of prime clinical importance. Methods This study included 13 ERS patients and 36 age- and gender-matched control subjects. We measured the height of J-wave and ST segment elevation (STE) remote from the VF episodes in patients with ERS. And the ER patterns of 13 ERS patients were compared between within days to hours to VF episodes (peri-event) and remote from the events (remote). Results The groups were male predominant (83.3%) and middle aged (47짹10 years). Patients and control subjects had similar pulse rate (61.3짹12.9 vs. 62.0짹7.9, p=0.858) and QTc intervals (399.3짹21.8 vs. 402.3짹14.5, p=0.662). J-wave or STE was mainly recorded in the lateral precordial leads in controls , while they were more evenly distributed in patients with ERS. There was no significant differences in highest amplitude (2.3짹1.6 vs. 2.4짹1.1, p=0.845) or sum of J-wave (5.4짹5.3 vs. 6.6짹3.5, p=0.345), number of leads with J-wave or STE (3.5짹1.7 vs. 3.9짹1.4, p=0.400). (Table 1) Peri-event ECGs were available in 12 out of 13 ERS patients. J-wave amplitudes (2.3짹1.6 vs. 3.8짹1.5, p= 0.025) and number of leads with J-wave or STE (3.2짹1.9 vs. 5.2짹2.8, p=0.044) were significantly higher around VF episodes than those remote from the events. (Table 2) Conclusion There were no specific ECG markers identifying patients with ERS from benign ER remote from VF events. However, extent of distribution and amplitude of J-wave or STE increased significantly around episode of VF. This narrow time window limits early detection of patients at risk of developing VF or sudden cardiac death.