Multiple Accessory Pathways in Children: Electrophysiological Features and Catheter Ablation Outcomes

Multiple accessory pathways (MAPs) may complicate electrophysiological assessment and catheter ablation in pediatric patients. We aimed to evaluate the clinical and electrophysiological characteristics, anatomical distribution, and procedural and follow-up outcomes of pediatric patients with MAPs.

This retrospective study included pediatric patients with at least two distinct accessory pathways identified during EPS between November 2019 and February 2026.

Of 1101 patients who underwent catheter ablation, 619 had accessory pathway-related arrhythmias; among these, 31 (5.0%) had MAPs. The mean age and body weight at the first procedure were 12.1 ± 3.6 years and 44.2 ± 18.8 kg, respectively, and 16 patients were female. Nine patients had structural heart disease, including seven with Ebstein anomaly. A total of 66 accessory pathways were identified: 28 patients had two pathways, two had three, and one had four. The right posteroseptal region was the most common pathway location (27.3%). One patient also had atrioventricular nodal reentrant tachycardia. Complete elimination of all accessory pathways was achieved in 29 of 31 patients (93.5%), and 63 of 66 pathways (95.5%) were successfully ablated. Recurrence occurred in six patients (19.4%). No procedure-related complications were observed during a mean follow-up of 26.3 ± 18.7 months.

MAPs were successfully treated with high acute success rates and no procedure-related complications. Nevertheless, recurrence and the identification of additional accessory pathways during subsequent evaluations remained clinically relevant, supporting the need for systematic post-ablation reassessment and long-term follow-up.