Reconstruction of the Right Ventricular Outflow Tract with a Transannular Patch for Ventricular Tachycardia Refractory to Radiofrequency Catheter Ablation in a Patient who Underwent Tetralogy of Fallot Surgery in Childhood

A 29-year-old male who underwent a complete tetralogy of Fallot repair at 2 years of age was referred to our hospital for treatment of sustained ventricular tachycardia (VT). The bipolar voltage map using an electroanatomical mapping system (CARTO, Biosense-Webster. during sinus rhythm revealed a low voltage area identical to the site of the right ventricular outflow tract (RVOT. patch on the anterior wall of the RVOT. During the tachycardia, the activation wavefront was found to revolve in a counterclockwise manner around the patch in the RVOT. Two radiofrequency catheter ablation (RFCA. sessions creating a line between the patch in the RVOT and pulmonary artery achieved only transient success. He underwent a pulmonary valve replacement and reconstruction of the RVOT with a transannular patch to treat the VT refractory to RFCA and severe pressure gradient in the RVOT. In postoperative electrophysiological study, a low voltage area in the RVOT connected to the pulmonary artery with the patch was observed, and produced conduction block in the reentry circuit of the VT. The patient has been free from any VT recurrence during 6 months of follow up.