Background: Cryoablation is increasingly used for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT). There are limited data regarding its efficacy and late outcomes in the pediatric population.
Methods: We reviewed the clinical records of 70 consecutive pediatric and adolescent patients (mean age: 12.2 ± 3, range: 5-19 years) with AVNRT, with or without additional structural heart disease, who underwent catheter ablation with the intention to use cryoablation as the primary modality between September 2004 and July 2011.
Results: The acute success rate was 97.14%. No long-term complications occurred. Patients were followed up for an average time of 46 ± 22.5 months (range 5-90). The recurrence rate was 16%, decreasing from 28% in the first 25 cases to 8.9% in the last 45 cases (p<0.05). Wenckebach point prolongation during cryoapplications was associated with a lower recurrence rate (p<0.05). No other risk factors for recurrence were identified, including persistence of slow pathway conduction. Patients with congenital heart disease had a similar success rate to patients with a structurally normal heart.
Conclusions: When applied to pediatric patients, cryoablation has an excellent success and safety profile, which can improve with increasing experience. Transient Wenckebach point prolongation during cryo-applications may be associated with improved late outcomes.