Catheter ablation of pediatric AV nodal reentrant tachycardia: results in small children.

BACKGROUND: AV nodal reentrant tachycardia (AVNRT) is commonly encountered in pediatric patients. Definite treatment can be achieved by catheter ablation. The purpose of the study was to evaluate the efficacy and safety of AVNRT ablation focusing on children with a body weight ≤25 kg.

PATIENTS AND RESULTS: Catheter ablation of AVNRT was attempted in 253 patients. Median age was 12.5 years; median body weight was 48.7 kg. 25 (9.9 %) children had a body weight ≤25 kg. Congenital heart disease was present in 6 patients (2.4 %). Procedural success was achieved in 98 % using radiofrequency, in 100 % using cryoenergy alone, and in 94 % using both energy sources. In patients with a body weight ≤25 kg, success was achieved in 96 %. In patients ≤25 kg, fluoroscopy and procedure duration did not differ from those >25 kg. The rate of major complications was significantly higher in the patients ≤25 kg (12 vs. 2.2 %, p = 0.04). Permanent AV block after RF ablation occurred in 2 patients with congenital heart disease and one infant with a body weight of 8.7 kg.

CONCLUSIONS: Catheter ablation of AVNRT in children and adolescents was safe and effective. Infants and small children with a body weight ≤25 kg had a higher prevalence of serious complications. This should alert physicians in decision making toward catheter ablation in these patients. In patients with congenital heart disease and different anatomy of the cardiac conduction system, operators must be aware of an increased risk for AV block.