Not all rotors, effective ablation targets for nonparoxysmal atrial fibrillation, are included in areas suggested by conventional indirect indicators of atrial fibrillation drivers: ExTRa Mapping project.

Background: Effects of nonparoxysmal atrial fibrillation (non-PAF) ablation targeting complex fractionated atrial electrogram (CFAE) areas and/or low voltage areas (LVAs) are still controversial. Methods and Results: A recently developed online real-time phase mapping system (ExTRa Mapping) was used to conduct LVA mapping and simultaneous ExTRa and CFAE mapping in 28 non-PAF patients after pulmonary vein isolation (PVI). Nonpassively activated areas, in the form of meandering rotors and/or multiple wavelets assumed to contain non-PAF drivers, partly overlapped with CFAE/LVAs but not always coincided with them. Conclusion: Real-time rotor imaging, rather than conventional indirect indicators only, might be very useful for detecting non-PAF drivers.