Focal impulse and rotor modulation for AF ablation: acute response in initial vs. rescue procedures

Abstract

Purpose: Focal Impulse and Rotor Modulation (FIRM) is a novel intervention designed to map and ablate presumed fixed sources of atrial fibrillation (AF). However it is not known if it should be part of initial AF ablation (abl) or reserved for rescue procedures only. In this study, we analyzed the mapping results and the acute response during FIRM-guided abl in initial vs. rescue patients (pts). Methods: From the CONFIRM multicenter registry, pts were divided into initial and rescue AF abl. AF was recorded using 64 pole basket and propagation maps created to identify rotors or focal sources. These were ablated for acute endpoint of AF termination or slowing (>10% CL increase). Following initial FIRM-guided abl PVI and linear lesions (in persistent AF) were also performed. Mapping data and acute response to FIRM abl were compared between the two groups. Results: The study (Table) consisted of 144 pts of whom 56 (39%) had 1.2±0.5 prior AF abl. There were no differences in age, gender, paroxysmal AF, LVEF or left atrial size between two groups. FIRM mapping found a similar number of left and right atrial sources, and abl at identified target sites resulted in a comparable high acute response of 83% vs. 86% in initial vs. rescue abl, respectively. View this table: Conclusion: FIRM technique provided valuable mapping data during both initial AF abl and after prior failed abl with equivalent high acute success. Prospective follow-up is underway to evaluate if acute success translates into comparable long-term response.