Posterior accessory pulmonary veins and atrial fibrillation.

of the right lower lobe, draining in the posterior aspect of the LA. The 4 PVs were electrically isolated by radiofrequency ablation, while sparing the accessory PV because of its small diameter and absence of electric activity in the interior. Accessory or supernumerary PVs can arise during embryologic development, and result in additional, separate openings of the LA with typically narrower atriovenous junctions. Knowledge of their existence can be useful to facilitate ablation, to avoid their inadvertent injury, and to assess the possibility that they might be a focus of automatism. Thus, the importance of image integration technology between navigators and CT/MRI is obvious.