Inducibility of ventricular arrhythmias in early repolarization syndrome and Brugada syndrome: From the J-wave associated with prior cardiac event (J-PREVENT) registry

BackgroundAlthough electrophysiological study is often performed in Brugada syndrome (BrS) to assess inducibility of ventricular arrhythmias (VA), the utility of electrophysiological study in early repolarization syndrome (ERS) remains unknown. The aim of the present multi-center observational study was to compare inducibility of VA in ERS with BrS, and to investigate any association between inducibility and recurrence of arrhythmic events in these patients.MethodsThe J-PREVENT registry consists of patients with early repolarization or Brugada type 1 ECGs, a history of prior cardiac events, and no structural heart disease. Patients in the registry with implantable cardioverter-defibrillators (ICDs) and who underwent electrophysiological study were enrolled. VA inducibility was assessed by programmed electrical stimulation performed at two different sites in the right ventricle with up to three extrastimuli. The occurrence of VA during follow-up was determined by interrogation of the patients׳ ICDs.ResultsOf the 79 patients studied (72 males, mean age 44±13 years), 21 patients (27%) had ERS, and 58 had BrS, 20 of whom also had early repolarization in the inferolateral leads. VA was induced in 9 patients (43%) and 45 (78%) with ERS and BrS, respectively (p=0.006). During a median follow-up of 1453 days, occurrence rate of VA was similar between ERS and BrS (p=0.35). Inducibility was not associated with occurrence of VA in either syndrome.ConclusionsIn patients with ERS with prior history of cardiac events, VA was induced in 43% of patients during electrophysiological study, approximately half that of BrS. Inducibility was not associated with occurrence of VA during follow-up, although this was true of BrS patients as well. Electrophysiological study may play a limited role in risk stratification in ERS.