Abstract
Background and aims: Complete isolation of the left atrial
posterior wall (LAPW) is challenging owing to overlapping epicardial
conduction. Peak frequency (PF) is a novel parameter that focuses on
near- and far-field electrogram components. In this study, we aimed to
determine whether transmural block completion is related to the ablation
site PF. Methods: We analyzed 44 consecutive patients
undergoing initial LAPW isolation between June 2023 and February 2024.
Pre-LAPW isolation and PF maps were obtained using an HD-Grid catheter.
In 17 of the 44 patients (Group-1), LAPW isolation was performed
conventionally. In the remaining 27 patients (Group-2), PF-guided LAPW
isolation was applied based on Group-1 results. Results: In
Group-1, the left atrial roof and floor line success rates were 58.8%
and 76.5%, respectively. The average PF value in the roof lines of
patients with a completed block line was significantly higher than that
of the remaining patients (286.6 ± 29.3 Hz vs. 236.1 ± 40.9 Hz, p =
0.012), but the floor lines were similar. In Group-2, relatively high PF
values were targeted to achieve complete block of the left atrial roof
and floor lines, following the results obtained in Group-1. The left
atrial roof line success rates (92.6% vs. 58.8%, p = 0.007), total
number of radiofrequency applications (22.7 ± 5.6 vs. 27.6 ± 8.5, p =
0.03), and procedural time (32.6 ± 18.3 vs. 47.9 ± 25.6 min, p = 0.03)
differed between Group-1 and Group-2. Conclusion: Using a PF
map for determining the optimal ablation line for LAPW isolation by
radiofrequency catheter ablation is feasible.