Abstract 4364823: Optimizing AV Nodal Ablation: The Role of Coronary Dominance in Procedural Planning

Background: The atrioventricular node artery supplies the atrioventricular node (AVN) and exhibits variability in origin and course as it may originate from the right coronary artery, left coronary artery or both. While the AVN is typically located within Koch’s triangle, multiple studies have demonstrated significant variability in its precise location. These anatomical variations may have substantial implications for procedures that require accurate localization, such as atrioventricular nodal (AVN) ablation. Although right-sided AVN ablation is the standard approach, up to 18% of cases require conversion to a left-sided approach. This is often due to procedural challenges in achieving adequate AV nodal conduction block and may ultimately increase procedure duration and radiation exposure. The aim of this study is to investigate the role of coronary dominance in the procedural planning and approach of AVN ablation. Methods: In this retrospective study, we included 132 patients who underwent AV nodal ablation and had a coronary computed tomography angiography (CTA) at William Beaumont University Hospital (Royal Oak, MI) over a three year period. Coronary CTA was performed either prior to or following AVN ablation and reviewed to determine coronary dominance. Patients were grouped based on coronary dominance: Group 1 (right dominant, n=104) and Group 2 (left or co-dominant, n=28). Numeric values were presented as mean ± SD and a paired Student’s t -test was used to compare modalities; significance was set at p < 0.05. Results: Group 2 patients had significantly higher odds of requiring left-sided AVN ablation compared to those in Group 1(21.4% vs. 1.9%, p <0.001). Mean total procedure time was longer in Group 2 (50 vs. 34 minutes, p =0.044), with a non-significant trend toward increased fluoroscopy time (10.4 vs. 7.9 minutes, p =0.311) and radiation exposure (1980 vs. 1350 cGy*cm2, p =0.372). No procedural complications were recorded. Conclusion: Coronary dominance may influence the anatomical location of the AVN and subsequently, the access site and procedural approach for AVN ablation. To our knowledge, this is the first study to explore the relationship between coronary dominance and procedural approach for AVN ablation. While limited by retrospective design, small sample size and anatomical variations of the AV node, this study suggests pre-procedural imaging may have a role in procedural planning and approach, improving procedural efficiency and safety.