Abstract 13615: Regional Onset of Atrial Fibrillation May Differ in Patients With Septal versus Left Atrial Triggers: A Biatrial Three Dimensional Noncontact Mapping Analysis
Introduction: Left atrial (LA) onset of atrial fibrillation (AF) has been documented with atrial premature beats (APBs) arising in the pulmonary veins (PV) but atrial tachyarrhythmias (ATs) or "rotors" initiating or maintaining AF with other extra pulmonary triggers have not been defined
Methods: We performed simultaneous contact catheter mapping of the RA and LA combined with 3 dimensional non-contact mapping (NCM - St. Jude Ensite Balloon Array) in 81 drug- refractory AF patients during spontaneous AF events. Spontaneous APBs & ATs/"rotors" were mapped to understand the roles of trigger and substrate for AF onset
Results: 81 pts with AF (paroxysmal, n =24; persistent, n= 57) were studied. A total of 137 APBs were recorded. A majority of the spontaneous APBs originated either from interatrial septum (IAS - Figure top right panel) (Gp. 1; n=49) or superior LA (SLA - Figure bottom right panel) (Gp 2; n=35). Gp. 1 and Gp. 2 APBs initiated stable spontaneous ATs (n=101) as shown in the figure (Figure - left panel). Gp. 1 pts were more likely to initiate both non-isthmus dependent ATs/"rotors"(n=19; 39%) and isthmus (n=13; 27%) dependent RA flutter, while Gp.2 pts initiated isthmus dependent type 1 RA flutter (n=18; 34%), non-isthmus dependent RA flutter (n=10; 19%), LA ATs/"rotors"(n=12; 23%) as well as superior LA/PV tachycardia (n=10; 20%). Non-isthmus dependent RA ATs/"rotors"were more common in Gp.1 pts (39% vs. 19%; p<0.05). Superior LA/PV tachycardia was more common in Gp. 2 pts (20% vs. 10%; p <0.05).
Conclusions: 1. Triggers from both the SLA and IAS initiate ATs/"rotors"s in both RA or LA. 2. Biatrial ATs/"rotors" are common with both types of APBs but their spectrum may differ with regional APB origin. 3. Limited ablation approaches directed solely at APB origins or local adjoining atrium may permit AF recurrences initiated by ATs/"rotors" involving more distant atrial substrates.
- © 2013 by American Heart Association, Inc.