Ventricular tachycardia originating from the “Bermuda Triangle”

Summary Idiopathic ventricular tachycardia originates from the right ventricular outflow tract (RVOT) in the majority of cases, but origins from structures adjacent to the RVOT are well known. The proximity of the posterior RVOT, the aortic cusps and the distal coronary s inus can render localisation of the true arrhythmia origin challenging. Although the diagnostic accuracy of the 12-lead ECG in localising the arrhythmia origin is i mperfect, it can be helpful in clinical practice. We d escribe a 25-year-old woman with tachycardia recurrence after an initially successful radiofrequency ablation (RFA) in the RVOT. The recurrent tachycardia had a slightly different morphology, with a larger R-wave in V1/V2 and an earlier R/S transition. The arrhythmia exit site, which had been presumed to be located b etween the RVOT and the distal coronary sinus, had been altered by the first RFA, and the focus was permanently eliminated by ablation from both sites (RVOT and distal coronary sinus) during the second procedure.