Single center experience of fluoroless AVNRT ablation guided by electroanatomic reconstruction in children and adolescents

Purpose: Anatomical considerations and risks related to x-ray exposure make atrio-ventricular nodal reentrant tachycardia (AVNRT) ablation in pediatric patients a concerning procedure. We aimed to evaluate the feasibility, safety and efficacy of performing fluoroless slow pathway cryoablation guided by the electroanatomic (EA) mapping in children and adolescents. Methods: Twenty one consecutive patients (mean age 13.5 + 2.4 years) symptomatic for AVNRT were prospectively enrolled to right atrium EA mapping and electrophysiological study prior to cryoablation. Cryoablation was guided by slow pathway potential and performed using a 4-mm tip catheter. Results: Sustained slow-fast AVNRT was inducible in all the patients with a dual AV nodal physiology in 95%. Acute success was achieved in 100% of the patients with a median of 2 cryo-applications. Fluoroless ablation was feasible in 19 patients, while in 2 subjects 50 and 45 seconds of x-ray were needed due to difficult vascular accesses. After a mean follow-up of 25 months AVNRT recurred in 5 patients. All the recurrences were successfully treated with a second procedure. In 3 patients a fluoroless cryoablation with a 6-mm tip catheter was success- fully performed, while in the remaining 2 patients a single pulse of 60 s of radiofrequency energy was applied under fluoroscopic monitoring. No complications occurred. Conclusions: Combination of EA mapping systems and cryoablation may allow to perform fluoroless slow pathway ablation for AVNRT in children and adolescents in the majority of patients. Fluoroless slow pathway cryoablation showed a high efficacy and safety comparable to conventional fluoroscopy guided procedures.