Abstract
BACKGROUND: Cryoablation is an alternative treatment for atrioventricular nodal reentrant tachycardia (AVNRT) and right anteroseptal and midseptal accessory pathways (APs) with a low complication rate. A high recurrence rate is still a concern in pediatric patients. METHODS: From February 2015 to March 2017, all consecutive patients who underwent cryoablation for supraventricular tachycardia were included in this study. The demographic and clinical data of the patients were reviewed. RESULTS: Fifty-two patients (AVNRT 43, anteroseptal and midseptal AP 9) were enrolled, including 24 males and 28 females. The median age at the time of the procedure was 15.6 years. For patients with AVNRT, 34 (79.1%) had the typical form, 5 had the atypical form (11.6%), and another 4 had both forms. For AP, four patients had right midseptal and 5 had right anteroseptal APs. The median total procedure time was 114 min (range 69-331 min), and the median fluoroscopy time was 25.9 min (range 9.2-99.6 min). After a median 6 attempts of cryomapping and 3 of cryoablation, the arrhythmia substrate was successfully ablated in 51 of 52 patients (98.1%). Ten developed transient second degree atrioventricular (AV) block and one developed transient third degree AV block, but none had permanent AV block or other complications. After a mean follow-up of 1.95 ± 0.54 years (range 1.1-2.86 years), there were three cases of recurrence (5.9%). The mean number of cryoablations decreased from 6.6 ± 6.4 (early group) to 3.1 ± 2.6 (late group) (p = 0.01) after a 1-year learning period. CONCLUSIONS: Cryoablation for AVNRT and anteroseptal and midseptal APs in pediatric and adolescent patients is safe and effective.