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Conventional ablation is less effective for persistent than paroxysmal atrial fibrillation (AF). However, several groups now show that stable rotors and focal sources sustain AF. We hypothesized that ablating AF sources at patient-specific sites should be similarly effective in eliminating paroxysmal or persistent AF (single procedure).
The Conventional Ablation with or without Focal Impulse and Rotor Modulation (CONFIRM) trial prospectively enrolled patients at 107 consecutive AF procedures (paroxysmal, n=31). FIRM-guided patients had ablation at 1-3 bi-atrial sources computed from real (contact) electrograms (RhythmViewTM, Topera, CA) then conventional ablation. FIRM-blinded patients (n=71) had only conventional ablation. Repeat procedures were not permitted.
Stable AF rotors or focal sources arose in 97% patients, often at unusual sites (fig A: posterior right atrium), more in persistent AF (2.2+/-1.0 vs 1.7+/-0.9, p=0.03). In Fig B and C, FIRM had similar efficacy for paroxysmal or persistent AF (83.3% vs 82.1 % freedom from AF), unlike conventional ablation (59.1 vs 37.8 %). Overall, AF freedom was 82.4% FIRM vs 44.9% (p<0.001).
Not only is FIRM-guided ablation more effective than FIRM-blinded ablation, but FIRM is the first strategy to show ∼80% single-procedure success in paroxysmal or persistent AF. Stable rotors and focal sources are core mechanisms for paroxysmal and persistent AF.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Arrhythmias: AF/SVT V
Abstract Category: 4. Arrhythmias: AF/SVT
Presentation Number: 1189-35
- 2013 American College of Cardiology Foundation