title: Catheter ablation of idiopathic left and right ventricular tachycardias in the pediatric population using noncontact mapping.
abstract: BACKGROUND
  Idiopathic ventricular tachycardia (VT) in children with a structurally normal heart can cause significant morbidity, and although rare, mortality. Conventional activation and pace mapping may be limited by nonsustained tachycardia or unstable hemodynamics.
  
  
  OBJECTIVE
  The aim of this study was to assess feasibility of catheter ablation of idiopathic VT in the pediatric population guided by noncontact mapping.
  
  
  METHODS
  Twenty consecutive pediatric patients with idiopathic VT underwent electrophysiologic study with the intention to use the noncontact mapping system EnSite 3000 (EnSite Array, St. Jude Medical Inc., Minneapolis, Minnesota). The multielectrode balloon array was introduced into the left or right ventricle, respectively, and tachycardia was analyzed using color-coded isopotential maps as well as reconstructed unipolar electrograms on the virtual geometry. The region of origin was identified in all of them, and the site of earliest activation with a QS pattern of the unipolar electrograms was guided for sites of ablation.
  
  
  RESULTS
  Idiopathic VT originated from the right ventricular outflow tract in 6 patients, from the left ventricle in 8, and from the aortic sinus cusp in 6 in this cohort with a median age of 14.4 (range: 4.8 to 20.9) years. Ablation was attempted in 18 of 20 children, and was acutely successful in 17 of these 18 (94%). During a mean follow-up of 2.3 +/- 1.7 years, VT recurred in 3, 2 of them have been treated with a second procedure, resulting in an overall intermediate-term success in 16 of 18 (89%) children with idiopathic VT.
  
  
  CONCLUSIONS
  Noncontact mapping can safely and effectively be used to map and guide catheter ablation of the tachycardia substrate of idiopathic VT in pediatric patients.
authors.affiliation: Department for Pediatric Cardiology and Intensive Care Medicine, Georg-August-University, Göttingen, Germany. hschnei5@gwdg.de
authors.forename: Heike E
authors.initials: HE
authors.lastname: Schneider
authors.forename: Thomas
authors.initials: T
authors.lastname: Kriebel
authors.forename: Klaus
authors.initials: K
authors.lastname: Jung
authors.forename: Verena D
authors.initials: VD
authors.lastname: Gravenhorst
authors.forename: Thomas
authors.initials: T
authors.lastname: Paul
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D018780:Body Surface Potential Mapping / Q000295:instrumentation / Q000379:methods*; D002037:Bundle-Branch Block; D017115:Catheter Ablation; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D004594:Electrophysiology; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000601:surgery; D006487:Hemostasis; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D055815:Young Adult