Spatial relationship between high-dominant-frequency sites and the linear ablation line in persistent atrial fibrillation: its impact on complex fractionated electrograms.

AIMS: Complex fractionated electrograms (CFEs) and high-dominant-frequency (DF) sites theoretically represent abnormal substrates and targets for atrial fibrillation (AF) ablation. The relationship between the high-DF sites in the left atrium (LA) and commonly used linear ablation line to the distribution of the CFEs in patients with persistent AF is unknown.

METHODS AND RESULTS: This study enrolled 62 persistent AF patients who underwent construction of LA CFE and DF maps (>350 points/map). Circumferential pulmonary vein isolation and linear ablation including that at the septum, roof, mitral-annulus, and ridge of the appendage were performed. Multipolar catheter mapping identified sites with high DFs (≥ 8 Hz) in all patients (9.8 ± 4.6/patient). In 47 patients in whom AF persisted despite ablation, there was a significant reduction in the continuous CFE (<50 ms) burden after the linear ablation (62 vs.11%; P < 0.0001), with a decrease in both the DF within the coronary sinus (6.9 ± 0.9 vs. 5.9 ± 0.8 Hz; P < 0.0001) and CFE surface area (42.8 ± 18.8 vs. 12.6 ± 10.5 cm(2); P < 0.0001). Comparing the high-DF sites with the ablated lesions, 64% of the high-DF sites (324 of 507) were on or adjacent to the ablation lines. Residual CFEs were observed in the infero-posterior regions in 83% of the patients. Almost half of the high-DF sites away from the linear ablation line were identified in the inferior (34%) and posterior (14%) LA regions.

CONCLUSION: Linear ablation resulted in the localization of the continuous CFE regions and reduced the global LA DF in patients with persistent AF. This may be related to the proximity relationship between the linear ablation lines and high-DF sites except for in the infero-posterior regions.