A case report of paroxysmal atrial fibrillation in three pulmonary veins presenting a common trunk

The pulmonary vein (PV) variant is present in 23-38% of patients who undergo atrial fibrillation ablation, and the common inferior PV (CIPV) variant is a rare PV variant that has been reported in 0.9-1.5% of patients. The arrhythmogenicity of the common trunk of the CIPV is unknown.

A 77-year-old woman underwent catheter ablation for paroxysmal atrial fibrillation (AF). Preoperative computed tomography revealed a common trunk from which the bilateral inferior PVs and a left superior PV originated. The voltage map of the left atrium (LA) showed three PVs stemming from a common trunk. There was a low-voltage area bounded by the common trunk entrance. An isolation line was created to connect the right superior PV and the common trunk. Twelve months later, AF recurred. The voltage map in second session showed residual irregular potentials at the boundary between the common trunk and the LA, and posterior wall isolation was performed. Postoperatively, the patient maintained sinus rhythm with no antiarrhythmic drugs during the 12-month follow-up period.

The CIPV is likely to predict the AF recurrence, even if preoperative voltage mapping shows a low voltage area. Substrate modification should be performed on abnormal potentials at the entrance of the common trunk, even though no potential is detected in the PVs or their antrum.