Catheter Ablation of AV-nodal reentrant Tachycardia in Children and Adolescents

Dual AV node pathways are a common substrate for supraventricular tachycardia (SVT) in children and adolescents. Definite treatment can be achieved by catheter ablation or modulation of the slow pathway.

A total of 255 EP studies (EPS) have been performed in 238 pediatric patients with dual AV node physiology during the last ten years at our institution. 26 children presented with a body weight < 25 kg. Primary endpoints of the procedure were either modulation or ablation of the slow pathway. Median age was 12.6 years, median weight was 49 kg. Indications for catheter ablation were patients/parents preference (75%) and drug refractory SVT (25%). Congenital heart disease was present in 11 cases (4%).

Acute procedural success was achieved in 98% with application of either RF or cryoenergy alone and in 94% using both energy sources. Acute success rate in patients with a body weight < 25 kg was 96%. Median fluoroscopy time was 10.1 min, median procedure duration was 178 min. Neither fluoroscopy time nor procedure duration were longer in patients with a body weight of < 25 kg. In two adolescent patients (0.8%) pacemaker implantation due to complete AV-block after RF application was necessary. In two patients (0.8%), drainage of significant pericardial effusion was necessary. Vessel injuries at the puncture site with need for surgical intervention occurred in 3 cases (1.2%). No ablation related coronary artery stenosis were evident on coronary angiography.

Catheter based ablation of AV nodal reentrant tachycardia in children and adolescents was safe and effective even in small children with a body weight < 25 kg. There was no difference in the rate of procedural success between the use of RF and cryoenergy. Complete heart block did not occur in patients < 25 kg but in two adolescent patients.