Cryoablation with an 8-mm tip catheter for typical AVNRT in children: a single center 5-year experience

J Interv Card Electrophysiol. 2021 Oct;62(1):113-122. doi: 10.1007/s10840-020-00868-x. Epub 2020 Sep 23.

Abstract

Background: In children with typical atrioventricular nodal reentrant tachycardia (tAVNRT), cryoablation is preferred over radiofrequency ablation (RFA) because of its safety profile and acceptable long-term success rates. In this study, we have assessed the utility of 8-mm tip cryocatheters for tAVNRT ablation in our center.

Methods: All pediatric AVNRT patients who underwent cryoablation with an 8-mm tip cryocatheter in our center between 2013 and 2018 were included. EnSite™ (St. Jude Medical Inc., St. Paul, MN, USA) was used in all patients.

Results: A total of 120 patients (64 females, 53%) were included in this study, and the mean age was 13.9 years with a standard deviation of 2.5 years. Eleven patients (9.1%) had structural heart disease, and 12 patients (10%) had additional arrhythmia substrate. The mean number of effective cryolesions was 8 with a standard deviation of 2.3. Fluoroscopy was used in three patients (2.5%). There were minor complications in only four patients (3.3%)-transient first-degree atrioventricular block or transient incomplete right bundle branch block. Acute success rate of cryoablation was 108/120 (90%). In twelve patients, cryoablation was suboptimal, or it failed. The procedure was completed successfully with RFA in the same session in ten patients. Overall acute success rate of ablation (Cryo ± RFA) was 98.5%. During a mean follow-up period of 24.6 months with a standard deviation of 11.3 months, three patients had recurrence (2.5%). Time between the beginning of the effective cryolesion and termination of AVNRT was found associated with acute success of cryoablation (p = 0.013).

Conclusions: Cryoablation of AVNRT with an 8-mm tip catheter in children appears to be safe, with an acceptable acute success rate and a low recurrence rate. A faster termination of AVNRT during the cryolesion, slowing down before ending with atrioventricular block, is a good indicator for acute success.

Keywords: 8-mm tip catheter; Cryoablation; Pediatric; Typical atrioventricular nodal reentrant tachycardia (tAVNRT).

MeSH terms

  • Adolescent
  • Catheter Ablation*
  • Catheters
  • Child
  • Cryosurgery*
  • Female
  • Humans
  • Recurrence
  • Retrospective Studies
  • Tachycardia, Atrioventricular Nodal Reentry* / diagnostic imaging
  • Tachycardia, Atrioventricular Nodal Reentry* / surgery
  • Treatment Outcome