Introduction: Pulmonary vein isolation (PVI) is associated with high recurrence rates in longstanding persistent atrial fibrillation (LPAF), possibly due to rotors in the posterior wall (LAPW). The objective is to describe the results of complete isolation of the LAPP on top if PVI.
Methods: Twenty five pts (mean age 65±12 y, 72% male, mean AF duration 16±3 months) underwent circunferential PVI after which two connecting ablation lines on the roof and the infero-posterior LA were performed to completely isolate the LAPW (Box Lesion). LAPW isolation was proved by eletrogram elimination, lack of capture during pacing and Adenosine infusion.
Results: After 12±2 months of follow-up, 19/25 pt (76%) were AF-free (19% off AADs) after a single procedure. Five pts (20%) had recurrences in the form of atrial flutter and were successfully ablated at the mitral isthmus, without recovery of conduction in the LAPW.
Conclusions: Complete isolation of the LAPW using the Box Lesion technique is associated with high sucess rates in pts with LPAF. Most recurrences occur as macroreentrant flutters outside of the ablated area (mitral isthmus).