title: Prospective assessment after pediatric cardiac ablation: recurrence at 1 year after initially successful ablation of supraventricular tachycardia.
abstract: OBJECTIVE
  A multicenter prospective study was performed to assess the results and risks associated with radiofrequency ablation in children. This report focuses on recurrences following initially successful ablation.
  
  
  METHODS
  Patients recruited for the study were aged 0 to 16 years and had supraventricular tachycardia due to accessory pathways or atrioventricular nodal reentrant tachycardia (AVNRT), excluding patients with more than trivial congenital heart disease. A total of 481 patients were recruited into the prospective cohort and were followed at 2, 6, and 12 months following ablation.
  
  
  RESULTS
  There were 517 successfully ablated substrates out of 540 attempted (95.7%). Loss to follow-up for individual substrates was 3.3%, 10.6%, and 21.2% at 2, 6, and 12 months, respectively. Recurrence was observed in 7.0%, 9.2%, and 10.7% of these substrates at 2, 6, and 12 months, respectively (adjusted for loss to follow-up as an independent source of data censoring). Recurrence rate varied by substrate location (24.6% for right septal, 15.8% for right free wall, 9.3% for left free wall, and 4.8% for left septal), as well as for AVNRT versus all others (4.8% vs 12.9%) at 12 months. The recurrence rate was higher for substrates ablated using power control but was not a function of whether isoproterenol was used for postablation testing.
  
  
  CONCLUSIONS
  Recurrence after initially successful ablation occurs commonly in children. It is least common after AVNRT ablation and most common following ablation of right-sided pathways. These results serve as a benchmark for the time course of recurrence following initially successful ablation of supraventricular tachycardia in children.
authors.affiliation: Department of Pediatrics, Division of Cardiology, Stanford University, Stanford, California, USA. George.Van.Hare@Stanford.edu
authors.forename: George F
authors.initials: GF
authors.lastname: Van Hare
authors.forename: Harold
authors.initials: H
authors.lastname: Javitz
authors.forename: Dorit
authors.initials: D
authors.lastname: Carmelli
authors.forename: J Philip
authors.initials: JP
authors.lastname: Saul
authors.forename: Ronn E
authors.initials: RE
authors.lastname: Tanel
authors.forename: Peter S
authors.initials: PS
authors.lastname: Fischbach
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Kanter
authors.forename: Michael
authors.initials: M
authors.lastname: Schaffer
authors.forename: Ann
authors.initials: A
authors.lastname: Dunnigan
authors.forename: Steven
authors.initials: S
authors.lastname: Colan
authors.forename: Gerald
authors.initials: G
authors.lastname: Serwer
mesh_terms: D000293:Adolescent; D017115:Catheter Ablation / Q000379:methods*; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D013617:Tachycardia, Supraventricular / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome