title: Slow pathway ablation in children with documented reentrant supraventricular tachycardia not inducible during invasive electrophysiologic study.
abstract: Radiofrequency catheter ablation (RFA) has become the procedure of choice for permanent therapy of atrioventricular nodal reentrant tachycardia (AVNRT). This report presents our experience with atrio-ventricular node (AVN) modification in patients with documented narrow complex reentrant SVT, but no evidence for an accessory pathway, and no inducible tachyarrhythmia during invasive electrophysiology (EP) study.
  
  
  METHODS
  The study population consists of nine children, age range 6-13 years (median 9) with previously documented SVT who had no tachyarrhythmia inducible during EP study (at baseline and following isoprenaline infusion). Eight of the 9 EP studies were performed under general anesthesia, and one under conscious sedation. An accessory pathway was excluded in all patients by appropriate atrial and ventricular extrastimulus pacing techniques. Eight of the nine patients had dual AV nodal physiology, and one had single AV nodal echo beats. The slow AV nodal pathway was empirically ablated, by applying RF lesions in the right inferoseptal AV groove, achieving catheter tip temperature of 50 degrees C. The appearance of an accelerated junctional rhythm during RF application was deemed to denote a successful application site. AV conduction during RF application was confirmed by incremental atrial pacing. The catheter position, and its relation to the compact AV node was constantly monitored using the LocaLisa navigation system. The end-point was absence of dual AVN physiology, and/or AV nodal echo beats.
  
  
  RESULTS
  Successful slow pathway ablation was achieved in all patients. One patient appeared to have two separate slow pathways with different locations and two AH-jumps, which were both successfully ablated. None of the patients had evidence of temporary or permanent AV block at follow-up (median duration 9 months, range 4 to 36 months); none has had recurrence of symptoms or documented tachyarrhythmia.
  
  
  CONCLUSIONS
  In children with structurally normal hearts, a previously documented SVT, absence of an accessory pathway and noninducibility of SVT during EP study, empirical slow pathway ablation appears to be justified.
authors.affiliation: Department Paediatric Cardiology, University Hospital of Cologne, Kerpener Str. 62, 50924 Köln, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Emmel
authors.forename: K
authors.initials: K
authors.lastname: Brockmeier
authors.forename: N
authors.initials: N
authors.lastname: Sreeram
mesh_terms: D000293:Adolescent; D001283:Atrioventricular Node; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis* / Q000601:surgery*; D013617:Tachycardia, Supraventricular / Q000175:diagnosis / Q000601:surgery; D016896:Treatment Outcome