Age related changes in the anatomy of the Triangle of Koch: Implications for Catheter Ablation of Atrioventricular Nodal Re-entry Tachycardia

Abstract Background: Atrioventricular nodal re-entrant tachycardia is the most common type of paroxysmal supraventricular tachycardia. We sought to assess whether important anatomical factors such as the location of the slow pathway, proximity to the Bundle of His and coronary sinus ostium dimensions varied with patient age and whether these impacted on procedural duration, acute success and complications. Methods: Baseline demographic and procedural data were collected and the maps were analyzed.. Linear regression models were performed to evaluate the associations between age and these anatomical variations. Associations were also assessed with age categorized as being greater than or equal to 60 years or less than 60 years. Results: The slow pathway was more commonly located in a superior location relative to the coronary sinus ostium in older patients. The location of the SP moved in a superior direction by 1mm for every increase in 2 years from the mean estimate of age.Additionally the slow pathway tended to be closer to the coronary sinus ostium in older patients and the diameter of the ostium was larger in older patients. This resulted in longer procedure time, ablation times and a greater need for long sheaths for stability. Conclusions: The location of the slow pathway is more superior and closer to the coronary sinus ostium with increasing age. Additionally the coronary sinus diameter increases with age. These factors results in longer ablation and procedural times in older patients.