Introduction of the Low Voltage Bridge Mapping for the AVNRT RF Ablation in Children - Early Follow-Up Results.

Background: Low voltage bridge mapping (LVBM) is an approach to atrio-ventricular nodal reentry tachycardia (AVNRT) ablation that has been postulated to facilitate the procedure. In our center, AVNRT ablations were performed with the traditional radio frequency current (RF) current approach using the CARTO mapping system. The use of LVBM in children has been well described with cryoablation but not with RF. LVBM was introduced in our center in April 2023 and is now routinely used for all AVNRT RF ablations. The aim of this study was to analyze how the introduction of the LVBM influenced the results of the pediatric AVNRT ablations using the RF current.

Methods: We analyzed all AVNRT ablations performed between January 1, 2019 and June 30, 2024, and compared traditional and LVBM approaches.

Results: The study group (LVBM) consisted of 40 and the control group of 61 children. Both groups did not differ significantly regarding age, body weight, and sex distribution. In the LVBM group, the total time of RF applications was significantly shorter (median of 120 s vs 191 s) and the number of RF applications was smaller than in the control group (median of: 4.5 vs 8). Total procedural time did not differ significantly between the groups. The success rate at 3 months follow-up was higher in the LVBM (92% vs 85%) group but failed to differ statistically. No complications were reported in either of groups.

Conclusions: The introduction of the LVBM in RF AVNRT ablations in children allows for limiting the number and time of RF applications required, without prolonging the total procedure time. Our experience shows LVBM can also be effectively used in RF ablations of AVNRT.