Continuous CFEs in the Vicinity of High DF Sites Are Important for the Maintenance of AF

In nonparoxysmal atrial fibrillation (AF), ablation of these continuous complex fractionated atrial electrogram (CFE) after PVI as an adjunctive therapy to PVI had a better long-term efficacy. However, the adjunctive role of dominant frequency (DF) mapping during CFE ablation of AF has not been clarified. The study enrolled 50 nonparoxysmal AF patients who underwent mapping, pulmonary vein isolation, and CFE ablation. High density DF and CFE mapping were performed from the center of DFmax centrifugally to the rest of the LA. The LA substrate was classified into two types depending on the presence of intra-LA DF gradients as type 1 (more than 20% of the average DF) or type 2 (less than 20%). In type 1 maximal CFE and DF gradients were observed at the boundary (28%) or center (32%) of the DFmax region. In type 2 (40%), less intra- LA DF gradient was observed and a large proportion of continuous CFEs extended from the center of DFmax. The procedure termination rate and long-term sinus rhythm maintenance rate were lower in patients with a smaller DF gradient (P<0.05). In conclusion, we found that the spatial distribution of fractionated activity was associated with particular DF patterns in nonparoxysmal AF patients. Individual knowledge of spatial and temporal organization of fibrillation waves in each patient may help in identification of mechanism and the critical targets for AF.