Identifying Driver Regions in Persistent Atrial Fibrillation: A Mosaic Pattern Within the Atrial Voltage Transition Zone

BACKGROUND AND AIMS: Driver-targeted ablation is a potential adjunct to pulmonary vein isolation (PVI) in persistent atrial fibrillation (PsAF), yet identifying drivers remains challenging. This study investigates whether voltage characteristics can facilitate driver identification. METHODS: In a multicenter retrospective exploratory cohort of 201 patients with PsAF undergoing PVI plus driver ablation, voltage characteristics within 241 driver regions were analyzed to derive an optimal voltage transition zone. A prospective validation cohort of 53 patients subsequently underwent ablation guided by this mapping approach. RESULTS: The optimal voltage threshold (0.16-0.61 mV) captured 78.8% of driver regions, which frequently exhibited a mosaic pattern at the interface of low-, transition-, and normal-voltage areas. This approach outperformed conventional low-voltage area-based identification (42.3%, p = 0.004). Mosaic pattern recognition using two voltage thresholds achieved 94.2% sensitivity and 77.1% specificity. Among cases without acute AF termination, the mosaic pattern was still observed in 87.5% of driver regions. In the validation cohort, acute AF termination (69.8%) and 12-month freedom from atrial arrhythmias were comparable to the exploratory cohort, though freedom from AF was lower (p = 0.035) but AF proportion among recurrences was reduced (p = 0.009). Procedure time and number of drivers ablated were also decreased (p = 0.001 and 0.003, respectively). CONCLUSION: This work proposes a hypothesis that AF driver regions in PsAF frequently exhibit a mosaic pattern under optimized voltage thresholds, which may provide a feasible adjunct to electrogram-guided mapping; whether this approach improves clinical outcomes remains to be determined.