Successful Radiofrequency Catheter Ablation for Macroreentrant Ventricular Tachycardias in a Patient with Tetralogy of Fallot After Corrective Surgery

CHINUSHI, M., et al .: Successful Radiofrequency Catheter Ablation for Macroreentrant Ventricular Tachycardias in a Patient with Tetralogy of Fallot After Corrective Surgery . Radiofrequency (RF) catheter ablation was applied to two macroreentrant ventricular tachycardias (VTs) documented after corrective operation for tetralogy of Fallot. The activation wavefront of VT with a right bundle branch block pattern was found to revolve in a clockwise manner around a presumed myotomy scar in the right ventricle, and VT with a left bundle branch block pattern revolved around the same anatomical obstacle in a counterclockwise manner. In both VTs, the biggest conduction delay was confirmed at the right ventricular outflow tract. RF applications to the slow conduction area terminated each VT within a few seconds but were insufficient to cure the VTs. RF lesions were then applied to the, slow conduction area in a line to intersect the macroreentrant circuit, and both VTs became noninducible.