Abstract 4360855: Advanced Mapping Techniques for Atrioventricular Nodal Reentrant Tachycardia in Pediatric Patients: Do They Make a Difference?

Introduction: Catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT) traditionally used a combination of anatomic and signal morphology mapping. Newer advanced mapping techniques (AMTs) for AVNRT include propagation mapping to identify the collision point of atrial wavefronts and voltage mapping to identify a low-voltage bridge. Due to very good outcomes of AVNRT ablation in general, assessment of the true value of AMTs is challenging. Hypothesis: AMTs improve procedural outcomes in pediatric patients and are viewed as valuable (both accurate and helpful). Aims: To describe outcomes for AVNRT ablations in pediatric patients with and without use of AMTs and to assess intraprocedural views on their value. Methods: Single-center retrospective study. Our center began almost exclusively using AMTs in AVNRT ablations in 2020, with both propagation and voltage mapping performed in these cases (AMT group: 2020-2024). A control group included the same number of the most-recent, consecutive, non-AMT procedures (2017-2022). Procedural outcomes were compared. In addition, the accuracy of AMT (whether combined pre-ablation AMTs correctly predicted the successful ablation location) and perceived helpfulness of AMT (as documented by the electrophysiologist at the time of the procedure) were assessed. Results: 99 AMT procedures and 99 controls were compared. Table 1 shows baseline characteristics while Table 2 shows procedural outcomes. There were no statistically significant differences in success rates or recurrences. Both the number and total time of RF and cryoablation lesions were greater in the AMT group. Median fluoroscopy time (9.9 v 13.8 min) and dose (1914 vs 4073 mGy-cm2) were lower in AMT procedures, but procedures lasted longer (133 v 109 min). AMTs were accurate in 52% of cases. When accurate, degree of helpfulness of AMT was categorized into three categories: 1.) helped identify the correct ablation location not suggested by traditional techniques in 23%; 2.) helpful but identified the same location as from traditional mapping in 17%, and 3.) unclear helpfulness in 11%. Conclusion: Only 52% of AMT localizations were viewed as accurate, but 23% were viewed as clearly helpful beyond traditional mapping techniques. AMTs correlated with reduced fluoroscopy but longer procedure times. The total number of ablation lesions and ablation times were higher in the AMT group and suggests that AMTs may adversely influence initial ablation locations.