Recurrent torsades de pointes after catheter ablation of incessant ventricular bigeminy in combination with QT prolongation

A 45-year-old woman, who had received a single-chamber implantable cardioverter defibrillator (ICD) due to ventricular fibrillation 5 years ago, was admitted for catheter ablation of incessant right ventricular outflow tract bigeminy. After successful ablation recurrent torsades de pointes associated with a prolonged corrected QT (QTc) interval were initiated by polymorphic premature ventricular complexes. Genetic testing revealed a heterozygous missense mutation in the SCN5A-gene (p.Arg190Gln, Exon 5), consistent with long QT-syndrome 3. DDDR pacing following implantation of an atrial lead prevented further ventricular tachyarrhythmias.