A Novel Mutation in the RYR2 Gene Leading to Catecholaminergic Polymorphic Ventricular Tachycardia and Paroxysmal Atrial Fibrillation: Dose-Dependent Arrhythmia-Event Suppression by β-Blocker Therapy

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic condition that presents with exercise-induced polymorphic arrhythmias. We describe a case report of a 25-year-old woman who had a cardiac arrest due to ventricular fibrillation. Genetic analysis revealed a novel missense mutation in exon 90 of the ryanodine receptor (RyR2) gene resulting in substitution of arginine for serine at residue 4153 (S4153R). The patient received an implantable cardioverter-defibrillator and low-dose beta-blocker therapy. She had recurrent polymorphic ventricular arrhythmias treated with appropriate cardioverter-defibrillator shocks and paroxysmal atrial fibrillation. Titration of beta-blocker to a much higher dose suppressed further episodes of ventricular arrhythmia and paroxysmal atrial fibrillation, resulting in reduction in device therapies.