Complex Electrical Substrates in Patients With High BMI and CHADSVASc Obscure Mapping of Rotational AF Drivers in Persistent AF

Introduction: Since traditional methods of mapping fail to reveal localized AF drivers, it is unexplained how ablation of limited areas guided by phase mapping can terminate persistent AF. We hypothesised that structural remodelling (LA size, raised BMI and high CHADSVASc) may reconcile traditional and phase mapping of AF. Methods: We recruited 60 patients at 5 international centers in whom persistent AF terminated by localized ablation (area Results: Each patient had AF termination (52% to sinus) by localized ablation, in whom we analyzed 550 activation (isochronal) maps. Unexpectedly, rotational sources were found by activation mapping, confirming phase maps in 15/60 (25%) cases (Figure A). Remaining cases had partial (45%) or no (30%) agreement (p 3 but not LA size or AF duration (table). Discussion: For the first time, this international study reveals rotational drivers of persistent AF by traditional mapping, focused at sites of known AF termination rather than arbitrary regions. However, traditional mapping was less sensitive than phase mapping for AF drivers, due to the impact of BMI and CHADSVASc substrates on electrograms. These data highlight the role of mapping technique in AF to guide ablation.