Propagation of meandering rotors surrounded by high dominant frequency areas in persistent Atrial Fibrillation

Background: identification of arrhythmogenic regions remains a challenge in persistent atrial fibrillation (persAF). Frequency and phase analysis allows identification of potential ablation targets. Objective: This study aims to investigate the spatiotemporal association between dominant frequency (DF) and re-entrant phase activation areas. Methods: Eight persAF patients undergoing first-time catheter ablation procedure were enrolled. A non-contact array catheter was deployed into the left atrium (LA) and 2048 AF electrograms (AEG) were acquired for 15 seconds following ventricular far-field cancellation. DF and phase singularity (PS) points were identified from the AEGs and tracked over consecutive frames. The spatiotemporal correlation of high DF areas and PS points was investigated and the organization index of high DF areas was compared with their periphery. Results: The phase maps presented multiple simultaneous PS points that drift over the LA, with preferential locations. Regions displaying higher PS concentration showed a degree of co-localization with DF sites, with PS and DF regions being neighbors in 61.8% and with PS and DF regions overlapping 36.8% of the time windows. Sites with highest DF showed a greater degree of organization at their core (CG) compared to their periphery. After ablation, the PS incidence reduced over the entire LA (36.2±23.2%, p<0.05), but especially at the pulmonary veins (PVs) (78.6±22.2%, p<0.05). Conclusions: Multiple PS points drifting over the LA were identified with their clusters correlating spatially with the DF regions. After PV isolation, the PS’s complexity was reduced, which supports the notion that PS sites represent areas of relevance to the atrial substrate.