Abstract 20829: Does PVI Work Only by Isolation? Panoramic Mapping Reveals Alternate Mechanisms Proven by Acute Termination of Atrial Fibrillation
Introduction: Pulmonary veins (PVs) are important to Atrial Fibrillation (AF). During PV ablation, however, AF often terminates before the PVs are isolated, inconsistent with trigger isolation alone. We hypothesized that panoramic mapping may a priori identify AF rotors located in PVs or on the trajectory of PV lesion sets, proven by the response of AF to ablation without PVI.
Methods: We performed bi-atrial contact mapping of patients at AF ablation, and identified those in whom rotors or focal tachycardia sources lay within or immediately adjacent to PVs and terminated acutely to sinus rhythm or organized atrial tachycardia during targeted ablation, prior to any other lesions.
Results: In 18 patients (average age 59.3, 38.9% persistent, 60% with LA enlargement), AF terminated (77.8% to sinus) during rotor ablation prior to PVI. Figure A shows the impact of ablating a rotor at the carina of the left PVs in a 61 year old man with persistent AF. Figure B shows the electroanatomical map for this patient with the site of termination (yellow). Electrograms at this termination site were fractionated, but this was variable for the group (p=NS). Vagal slowing was predominantly absent at termination sites (p<0.05). Figure C shows sites of termination in the LA for the group, in relation to a standard PV lesion set. These sites represented < 50 % of all AF terminations by rotor-guided ablation, consistent with studies from other groups.
Conclusions: We demonstrate an alternative mechanism for the success of PV ablation. Localized substrates for AF near PVs explain why AF may terminate before PVs are isolated, and why patients post-PV ablation may be arrhythmia-free despite PV reconnection. Identification of such sites may enable reinforcement of ablation at these sites to improve outcome.
Author Disclosures: R. Navara: None. G.C. Leef: None. F. Shenasa: None. C. Kowalewski: None. T. Baykaner: Research Grant; Significant; Heart Rhythm Society Clinical Research Fellowship. J. Zaman: Research Grant; Significant; Fulbright Commission, British Heart Foundation. S. Narayan: Research Grant; Significant; National Institute for Health. Honoraria; Modest; Medtronic, St Jude Medical, Biotronik, Boston Scientific Corp. Ownership Interest; Significant; Topera Inc.
- © 2016 by American Heart Association, Inc.