title: Cryoablation versus radiofrequency ablation for atrioventricular nodal reentrant tachycardia in children: long-term results.
abstract: BACKGROUND
  Cryoablation is used increasingly for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT). We sought to compare the long-term outcomes of cryoablation (Cryo) vs. radiofrequency (RF) ablation for the treatment of AVNRT in children.
  
  
  METHODS
  Two groups of consecutive patients were analyzed retrospectively: the RF group, 20 patients (60% males, mean age 13.25 +/- 2.59 years), and the Cryo group, 20 patients (55% males, mean age 12.17 +/- 3.07 years). Follow up was 52.7 +/- 16.5 months for the RF and 32.8 +/- 11.9 months for the Cryo group.
  
  
  RESULTS
  Acute success rates (100% for RF vs. 90% for Cryo), procedural times (147.75 +/- 37.15 min for RF vs. 184.4 +/- 75.59 min for Cryo), and fluoroscopy times (10.9 +/- 6.46 min for RF vs. 6.41 +/- 6.92 min for Cryo) were not statistically significantly different between the two groups. The number of lesions was significantly higher in RF than in Cryo (8.85 +/- 6.63 vs. 3.6 +/- 1.9, p=0.007). Transient AV block during ablation occurred in 1 patient in each group. No permanent AV block was observed. Recurrence rate was 10% in the RF and 27.7% in the Cryo group (p=0.222) occurring up to 14 months after the procedure.
  
  
  CONCLUSIONS
  Cryoablation is safe and effective for the treatment of AVNRT in pediatric patients, but there is a tendency for higher recurrence rates compared to radiofrequency ablation. Techniques to reduce recurrence rates after cryoablation are needed.
authors.affiliation: Division of Pediatric Cardiology, Mitera Children's Hospital, Athens, Greece. papagi@otenet.gr
authors.forename: John
authors.initials: J
authors.lastname: Papagiannis
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Papadopoulou
authors.forename: Spyridon
authors.initials: S
authors.lastname: Rammos
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Katritsis
mesh_terms: D000293:Adolescent; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000209:etiology / Q000628:therapy*; D013997:Time Factors