Oral Adrenergic Agents Produced Ventricular Fibrillation and QT Prolongation in an Elderly Patient Carrying an RYR2 Variant

Abstract

Mutant cardiac ryanodine receptor channels (RyR2) are "leaky," and spontaneous Ca²⁺ release through these channels causes delayed afterdepolarizations that can deteriorate into ventricular fibrillation. Some patients carrying RYR2 mutations in type 1 catecholaminergic polymorphic ventricular tachycardia exhibit QT prolongation and are initially diagnosed with long QT syndrome. However, none have been reported to cause drug-induced ventricular fibrillation in patients with RYR2 variants. We describe the first case of an elderly woman with drug-induced QT prolongation and ventricular fibrillation who carried a novel RYR2 variant but no other mutations related to long QT syndrome. Oral adrenergic agents might induce QT prolongation and subsequent ventricular fibrillation in patients carrying an RYR2 variant. Screening for RYR2 could be valuable in patients with suspected drug-induced long QT syndrome.