Spatial displacement on three-dimensional maps caused by rhythm differences in premature ventricular contraction ablation.

Introduction: Three-dimensional (3D) maps are useful for premature ventricular contraction (PVC) ablation. However, positional information changes compared with sinus rhythm when PVCs appear, rendering ablation difficult. We aimed to understand the spatial displacement characteristics of PVC ablation in 3D maps and the therapeutic effect after correction using the LAT-Hybrid function.

Methods: Thirty-two consecutive patients who underwent PVC ablation from 2022 to 2024 were included. Parallel mapping was used to analyze the LAT-Hybrid function. Ablation was performed at the best Hybrid-LAT location. Characteristics according to PVC origin (right ventricular outflow tract, ventricular septum, and left ventricular outflow tract/left ventricular summit) were compared. Efficacy was evaluated by acute response and clinical outcome on 24-h Holter after 6 months.

Results: In all cases, the PVC origin was spatially displaced by 5.6 ± 1.9 (right ventricular outflow tract, 6.0 ± 1.8; ventricular septum, 4.0 ± 1.4; left ventricular outflow tract/left ventricular summit, 6.0 ± 1.7) mm, and the septum area was significantly smaller. The voltage of origin was 60% in the low voltage-transitional zone, which coincided with 80% of the origin determined from the ripple map. The pace map at the location analyzed with LAT-Hybrid was high at 95.4% ± 3.6%, and ablation was successful in 96.9% at the same site. The clinical outcome was good 6 months after ablation.

Conclusion: Spatial displacement of the 3D map caused by differences in excitation propagation can lead to misidentification of the origin. PVC ablation corrects spatial displacement and obtains accurate positional information, leading to successful ablation.