Comparison of first deflection annotation algorithm and near-field annotation algorithm in premature ventricular complex ablation

BACKGROUND Accurate identification of the earliest activation site is essential for successful catheter ablation of premature ventricular complexes (PVCs). OBJECTIVE To compare First Deflection (FD) and Near-Field (NF) detection using the Turbomap modality on the Ensite X system. METHODS A retrospective analysis was conducted on 59 patients (71 ablation sites) who underwent first-time PVC ablation. All cases were remapped using Turbomap to extract FD and NF parameters at the earliest activation sites. Comparisons were based on differences in local activation time (ΔLAT), peak frequency (Δ peak frequency), activation area (Δ activation area), and spatial distance. RESULTS FD detection identified significantly earlier LAT (-37.8 ± 14.7 msec vs. -27.9 ± 12.4 msec, p < 0.001). Conversely, NF detection detected a higher peak frequency (249.7 ± 102.8 Hz vs. 219.3 ± 103.9 Hz, p = 0.044). No significant differences were observed in the area of the earliest activation within 5 msec between techniques. When cases were categorized by PVC origin (RVOT vs. LV summit) and by ablation strategy (single-chamber vs. multi-chamber ablation), no significant differences in mapping parameters were found. However, a shorter distance between the FD- and NF-annotated earliest activation sites was significantly associated with successful PVC elimination within two ablation attempts (3.1 ± 2.7 mm vs. 8.3 ± 5.0 mm, p < 0.001). CONCLUSION FD detection provides earlier LAT activation, while NF detection captures higher-frequency signals. Closer spatial correlation between FD and NF may predict more efficient ablation, even though mapping parameters did not differ significantly across categorized groups.