Two decades of experience on ablation in children with Ebstein's anomaly

Accessory pathways are commonly seen due to delamination of tricuspid valve leaflets. In addition to accessory pathways, an enlarged right atrium due to tricuspid regurgitation and incisional scars creates substrates for atrial re-entries and ectopic tachycardia. We sought to describe our experience with catheter ablation in children with Ebstein's anomaly.

During the study period, of 89 patients diagnosed with Ebstein's anomaly, 26 (30.9%) of them who underwent 33 ablation procedures were included in the study. Accessory pathways were observed in the majority of procedures (n = 27), whereas atrial flutter was observed in five, atrioventricular nodal reentrant tachycardia in five, and atrial tachycardia in two procedures. Accessory pathways were commonly localised in the right posteroseptal (n = 10 patients), right posterolateral (n = 14 patients), septal (n = two patients), and left posteroseptal (n = one patient) areas. Multiple accessory pathways and coexistent arrhythmia were observed in six procedures. All ablation attempts related to the accessory pathways were successful, but recurrence was observed in five (19%) of the ablations. Ablation for atrial flutter was performed in five patients; two of them were ablated successfully. One of the atrial tachycardia cases was ablated successfully.

Ablation in patients with Ebstein's anomaly is challenging, and due to nature of the disease, it is not a rare occasion in this group of patients. Ablation of accessory pathways has high success, but also relatively high recurrence rates, whereas ablation of atrial arrhythmias has lower success rates, especially in operated patients.