A Stepwise Approach to Catheter Ablation of Avnrt in Children

Alfredo Di Pino, Elio Caruso
Pediatric Cardiology, Centro Cardiologico Pediatrico del Mediterraneo, Italy

Aim: To evaluate the safety and mid-term efficacy of a stepwise approach to catheter ablation of AVNRT in children using radiofrequency (RF) as first line energy source at posterior sites followed by cryoablation (Cryo) in case of failure or when moving to the midseptal area.

Methods and Results: A retrospective analysis of 33 pediatric patients (pts)(mean age 13± 3 years; range 7-18) undergoing catheter ablation of AVNRT between August 2013 and June 2015.

Of the 33 pts, 18 (54%) were ablated without a stepwise approach (using only cryoenergy), while for 15(46%) the described stepwise algorithm was used. There were no pre-procedural identifying characteristics of this group.

Of these 15, AVNRT was inducible in 10 (66%), while 5 had dual AV node physiology plus either: inducibility of single nodal reentry beats (n=2); typical symptoms (n=2); or previous documented AVNRT (n=1). The procedural endpoints for success were the lack of inducibility (inducible pts), and slow pathway ablation or modulation (non inducible pts). Clinical end-points were the absence of AVNRT recurrences and/or symptom resolutions during follow-up.

RF application at posterior sites was acutely efficacious in 11 pts (73%) with a mean of 2±1 applications. Cryoablation was added in 5 pts: to eliminate AVNRT induction in 4 and to eliminate the slow pathway and single AVN echo beats in 1.The overall acute success was 100%.

The mean procedure time was 132 ± 35 minutes (range 75-180). The mean fluoroscopy time was 9 ± 18 minutes (range 0-58 min). A transient 1°/ 2° degree AV block was observed in 4 pts (3 Cryo/1RF). After a mean follow-up of 12±8 months (range 2-24 months) no recurrence of sustained palpitations or documented AVNRT were observed.

Conclusion: A stepwise approach to ablation for AVNRT using RF at posterior sites and Cryo in the mid-septal area can be safe and highly effective in pediatric patients.