Impact of Infero/Lateral Early Repolarization Pattern in Patients with Brugada Syndrome

Background: Inferolateral early repolarization (ER) pattern is often observed in Brugada syndrome (BrS). However, its clinical implication in this syndrome is still controversial. Method: Total two-hundred forty five Brugada ECG patients (mean age 48 years, men/female=235/10), including documented ventricular fibrillation (VF) in 27, were evaluated. Infero/lateral ER pattern was defined as a notched or slurring>1mm J-wave at least consecutive two of inferior (II, III, aVF) or lateral (I, aVL, V4, V5, V6) leads. The presence of this ER pattern was compared with clinical, electrocardiographic and genetic parameters. Results: Infero/lateral ER pattern was observed in 25 (10.2%) BrS patients (inferior leads in 12, lateral leads in 11 and both in 2) and was significantly associated with patients of documented VF (P<0.01) and with prolonged PQ interval (P<0.04). However they were not associated with the frequency of spontaneous type-1 ECG, wide QRS complex (>120ms), family history of sudden death, positive late potential on signal averaged ECG and SCN5A mutation. Increased number of positive ER leads have a trend of increasing documented VF patients (>3 leads; 54%). Conclusion: These data indicates that infero/lateral ER reflects the expansion of repolarization abnormality in the ventricle and may be associated with high-risk phenotype in BrS.