〈Case Reports〉Catheter Ablation of Dual-Loop Macro-Reentrant Tachycardia under Electroanatomical Mapping Guidance Using Multiple-Electrode Sampling Catheter in Enlarged Right Atrium after Repair of Tetralogy of Fallot : A Case Report

publisher〈Abstract〉We describe a 47-year-old woman who underwent tetralogy of Fallot repair at the age of 6 years and radiofrequency catheter ablation of macro-reentrant right atrial tachycardia (rt-AT) 41 years after surgery. A three-dimensional electroanatomical mapping system helped to determine the macroreentrant circuit. Although the right atrium was enlarged by the burden on the right side of the heart, multiple samplings on contact bipolar electrograms generated using a multipolar catheter enabled the production of high-density activation and voltage maps (429 points) within 30 minutes. The activation map revealed a dualloop reentrant circuit surrounding the superior and inferior vena cava, and clarified a critical isthmus located in the low-voltage area on the postero-lateral side of the right atrium. The rt-AT was terminated by ablation of the isthmus without damaging the nearby right phrenic nerve