Patients with long QT syndrome can sometimes present with a ventricular fibrillation (VF) storm. Catheter ablation of culprit premature ventricular complexes responsible for the triggering of the VF episodes may be required in rare cases of electrical storm that do not respond to conventional measures, and this can be life-saving. We describe a case of emergency catheter ablation in a young woman with a normal corrected QT interval, who presented with malignant VF storm for the first time. We also discuss the diagnostic and management challenges involved, as well as the value of genetic testing in refining the diagnosis. Keywords: catheter ablation, long QT syndrome, ventricular fibrillation Singapore Med J 2013; 54(1): e1-e4 Singapore Med J 2013; 54(1) : e2 C a s e R e p o r t