Mutant cardiac ryanodine receptor channels (RyR2) are “leaky,” and spontaneous Ca2+ release through these channels causes delayed afterdepolarizations that can deteriorate into ventricular fibrillation (VF). RYR2 is a causative gene of type 1 catecholaminergic polymorphic ventricular tachycardia (CPVT). Some patients carrying RYR2 mutations in CPVT exhibit QT prolongation and are initially diagnosed with long QT syndrome. However, none have been reported to cause drug-induced VF in patients with RYR2 variants. We describe the first case of an elderly woman with drug-induced QT prolongation and VF who carried a novel RYR2variant but no other mutations related to long QT syndrome.