Effect of flecainide on suppression of ventricular fibrillation in a patient with early repolarization syndrome

Abstract

Early repolarization syndrome (ERS) is defined as a condition demonstrating an early repolarization (ER) pattern, that is, a distinct J-point elevation > 0.1 mV from the isoelectric line resulting in a notch or slur of the terminal QRS and/or ST-segment elevation in at least 2 adjacent leads, associated with ventricular tachycardia or ventricular fibrillation (VF) attacks.(1) Brugada syndrome (BrS) is another familial arrhythmia syndrome that has a pathognomonic coved-type R'-ST segment not explained by other identifiable causes and is related to fatal ventricular tachyarrhythmias.(2) These 2 disease entities have been suggested to share a similar clinical phenotype and underlying pathophysiologic mechanisms, but they show differences in some aspects. An implantable cardioverter-defibrillator (ICD) is the first choice for patients with ERS or BrS presenting with sudden cardiac arrest or documented ventricular tachyarrhythmias.(4) It is not uncommon for antiarrhythmic drugs to be required to prevent potentially fatal arrhythmic storms even when an ICD has been implanted. Flecainide, a class IC antiarrhythmic drug, is contraindicated in BrS because it is proarrhythmic, but at the same time it has been suggested to attenuate the degree of J-point elevation in ERS.(3) However, its clinical benefit has not yet been reported. Recently, we encountered a young man with ERS who responded well to oral flecainide.