Left atrium electrical isolation as a complication of catheter ablation of persistent atrial fibrillation.

We report a case of left atrium electrical isolation occurring during the procedure of percutaneous transcatheter ablation of atrial fibrillation (AF). After completion of circumferential pulmonary vein ablation (CPVA) and linear ablation, the septal areas were critically ablated for complex fractionated atrial electrograms (CFAEs). The lesions on the septum together with all the ablation lines completely blocked the interatrial conduction through Bachmann's bundle (BB) and the septum, resulting in electrical isolation of the left atrial (LA) wall and LA appendages. Avoiding a large septal area ablation may avoid left atrial electrical isolation.