Cryoablation has become a preferred approach for managing atrioventricular nodal reentrant tachycardia (AVNRT) in children due to its safety and durable outcomes. A six-year single-center study published in Pacing and Clinical Electrophysiology now shows that catheter tip size does not influence procedural success or long-term efficacy.

The study analyzed 129 pediatric patients (76 female, mean age 13 ± 3 years, mean weight 51.7 ± 15.7 kg) who underwent cryoablation between January 2016 and December 2022. A 6-mm catheter was used in 64 patients and an 8-mm catheter in 65. Procedures were performed using the EnSite three-dimensional electroanatomical mapping system with minimal or no fluoroscopy, reducing radiation exposure. Typical AVNRT accounted for 97.7% of cases, while 2.3% were atypical.

The mean procedure time was 151.9 ± 43 minutes, and the mean number of cryolesions was 8.5 ± 2.3 with 6-mm catheters and 9.0 ± 2.5 with 8-mm catheters. Acute success reached 100% in the 6-mm group and 98.5% in the 8-mm group (p > 0.05). During a 31.4 ± 26-month follow-up, six patients (4.6%) experienced recurrence, all successfully re-ablated. The overall long-term success rate was 94.4%, and no permanent complications were observed. One child developed a transient atrioventricular block that resolved spontaneously.

These findings affirm that both 6-mm and 8-mm cryoablation catheters provide high efficacy and safety in pediatric AVNRT. Catheter selection can be guided by patient anatomy and operator preference without compromising clinical outcomes.