Arrhythmia mechanisms and results of transcatheter ablation therapy in patients diagnosed with CHD: the most difficult and dark side of paediatric electrophysiology

Abstract Aim: This study aimed to evaluate the characteristics, difficulties, and outcomes of patients who underwent transcatheter ablation treatment due to arrhythmia with a diagnosis of CHD. Methods: A total of 166 patients (189 substrates) with CHD who underwent catheter ablation between November 2013 and 2023 were evaluated retrospectively. EnSite™ (St Jude Medical Inc., St Paul, MN, USA) was used in all patients. Results: The mean age was 14.8 ± 7.9 years (2.9–43 years). The most common CHD’s were Ebstein anomaly ( n : 40), tetralogy of Fallot ( n : 31), atrial septal defect ( n : 25), ventricular septal defect ( n : 22), great artery transposition (D/L TGA, n : 12), and complex CHD in single ventricle physiology ( n : 9). The most common arrhythmia mechanisms were Wolf-Parkinson-White syndrome (WPW, n : 50), intraatrial reentrant tachycardia (IART, n : 39), typical atrioventricular nodal reentrant tachycardia (AVNRT, n : 37), and ventricular tachycardia-ventricular extrasystoles (VT/VES, n : 23). There was more than one arrhythmia in 23 patients and multiple manifest accessory pathways in 10 patients. The average procedure time was 174 ± 69.3 minutes, and the average fluoro time was 8.3 minutes. While successful ablation was performed in 176/189 (acute success 93.1%) substrates, the procedure was unsuccessful in five patients and suboptimal in eight patients. Recurrence was observed in 11 patients (6.4%) during a mean follow-up period of 49.2 ± 30.1 months. A second ablation was performed on 13 patients. Acute success was achieved in all except one patient. A total of 11 patients are being followed up with medical treatment. Conclusion: Despite the complex anatomy, age, operations, and limited vascular access possibilities in patients diagnosed with CHD, transcatheter ablation treatment with advances in electrophysiology, the introduction of different energy types, special ablation catheters, multipolar mapping catheters, and 3D nonfluoroscopic mapping systems seems to be a safe and effective option.