Po-02-122 tracking and ablating the muscle sleeve/fascicle for pulmonary vein isolation

Pulmonary vein isolation (PVI) remains the cornerstone for atrial fibrillation (AF) ablation. However, it yields unsatisfactory outcomes requiring repeat procedures especially in persistent AF. Additional linear ablation, or of complex fractionated atrial electrograms, atrial rotors or ganglionated plexi prolongs procedure time and increases complications with small additional benefits. We evaluated the efficacy of a new method of tracking and ablating pulmonary vein (PV) muscle sleeve/fascicle followed by wide area circumferential ablation (WACA) as a method of treatment of AF. To track a muscle sleeve/fascicle, a Lasso catheter was placed into one PV and based on the electrograms pattern on the catheter, sites of exit of muscle sleeves/fascicles were determined along the wide area circumferential ablation (WACA) line. (Panel A of figure shows the electrogram pattern, which suggests two muscle fascicles [red and blue arrows]). Focal ablation at sites on the planned WACA line was then performed to interrupt the muscle sleeve/fascicle connection with atrium (Panel B and C of figure shows point ablation resulting in partial and complete isolation; black arrow marks the location of ablation catheter). The same method was repeated to the ipsilateral PV before full WACA of both PVs was commenced. The strategy was repeated on the contralateral PVs. Ablation of these fascicle-atrium connections resulted in PVI isolation before WACA was completed in all 18 patients. Intravenous adenosine was used at the end to elicit dormant PV connections. We schematically labeled the areas around the PVs into zones and summarized the location of these muscle fascicles in each patient. (Panel D; each dot represents a fascicle and color matches with the PV with which it is associated). Eighteen patients (61±11 years old, 56% male) with AF (12 persistent {67%}) were analyzed in this study. Fascicles were identified in all patients and focal ablation of fascicles resulted in isolation of the PVs. In addition to PVI, 8 had Cavotricuspid isthmus ablation, 1 for right focal atrial tachycardia (AT), one left focal AT, and 1 for biatrial reentrant AT. With a follow-up of 155 ±120 days, 83% of paroxysmal and 75% of persistent AF remained in sinus rhythm. Left atrial dwell time for PVI alone was less than 2 hrs and no complications were seen. The tracking and ablating muscle sleeve/fascicle before performing WACA is a strategy with outcomes superior to previously reported in literature.