Complex Fractionated Electrogram Distribution and Temporal Stability in Patients Undergoing Atrial Fibrillation Ablation

Background: Targeting of complex fractionated electrograms (CFEs) has been described as an approach for catheter ablation of atrial fibrillation (AF); however, the distribution and temporal stability of CFE regions remain poorly defined. Methods: In patients with persistent AF referred for ablation, we performed two consecutive left atrial (LA) CFE maps prior to AF ablation. Bipolar electrograms were acquired during AF, and the mean AF cycle length and electrogram voltage were automatically determined at each point. Sites with mean CL ≤120 ms were considered CFE positive. The two maps were then compared qualitatively and quantitatively. Results: A total of 15 patients (93% male, age 56.1 ± 9.0 years) undergoing AF ablation were studied. The two maps were separated in time by 31 ± 10 minutes. There was no significant difference in the number of CFE‐positive regions (12.3 ± 5.2 vs 11.3 ± 4.7; P = 0.06) between the maps. While CFEs were widely distributed within the LA, the PV/left atrial junction (73%) and left atrial appendage (77%) were most often CFE positive. The presence of CFEs at each region was concordant 78% of the time. There was a significant correlation between the two maps (r = 0.35 ± 0.21, range 0.1–0.84; P < 0.001) with a percent difference of 17.5 ± 9.4%. Conclusions: During persistent AF, most CFE regions are found in the vicinity of the PVs. There is a significant correlation between two CFE maps constructed 31 minutes apart, with 78% concordance of CFE sites.