ERS in Relation to Brugada Syndrome

Early repolarization (ER) is a common electrocardiographic finding characterized by elevation of the J point with notching or slurring on the electrocardiogram (ECG) followed by ST-segment elevation. Although this condition has been considered benign, Haissaguerre et al. demonstrated that patients with J waves in the inferolateral leads were likely to be associated with idiopathic ventricular fibrillation (VF) and reported this entity as inferolateral early repolarization syndrome (ERS) in 2008. Brugada syndrome (BrS) is another clinical entity that causes sudden death due to VF in patients with apparently structurally normal hearts and is characterized by coved ST-segment elevation in the right precordial leads. ERS and BrS are considered to share a similar genetic background and to represent a continuous spectrum of phenotypic expression. However, the exact pathophysiological mechanisms underlying ERS and BrS remain unknown, and some clinical manifestations reportedly differ between these syndromes. In this chapter, we introduce our current understanding of ERS and BrS.