title: Magnetic navigation in AV nodal re-entrant tachycardia study: early results of ablation with one- and three-magnet catheters.
abstract: OBJECTIVE
  Steering soft, flexible catheters using an external magnetic field could have advantages for heart catheterization, especially for therapy of tachyarrhythmias. Our aims were to assess the feasibility of magnetic navigation to Koch's triangle and reliable ablation of atrioventricular nodal re-entry tachycardia (AVNRT) with a magnetic catheter.
  
  
  RESULTS
  Consecutive patients with AVNRT were mapped and ablated with a magnetically enabled catheter (Helios I or II), with, respectively, one and three magnets at the tip. The catheter was remotely advanced with the Cardiodrive system and orientated with the Navigant control system. After initial positioning with the external magnets, adjustment was made in 5 degrees steps. Success rates, procedure, and fluoroscopy times were analysed, and compared with a local contemporary series of conventional AVNRT ablations. Magnetic navigation was feasible in all 20 patients. Targets were easily reached. Catheters remained stable in position during accelerated junctional rhythms. Ablation was successful in 18/20 procedures (90%). No significant complications occurred. Median patient fluoroscopy time was 12 min, median physician fluoroscopy time was 4 min. Fluoroscopy times tended to be shorter than that in the conventionally treated group. Procedure duration decreased significantly over time, median procedure time was similar to that in the conventional group.
  
  
  CONCLUSIONS
  AVNRT can be successfully mapped and ablated using magnetic navigation. A learning curve was evident, unrelated to catheter type, but to increasing operator experience. Physician radiation times were one-third of patient times. No complications occurred. Procedure time is comparable with that of conventional ablation.
authors.affiliation: Clinical Electrophysiology Unit, Department of Cardiology, Thoraxcentre, Erasmus MC, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. a.thornton@erasmusmc.nl
authors.forename: A S
authors.initials: AS
authors.lastname: Thornton
authors.forename: P
authors.initials: P
authors.lastname: Janse
authors.forename: D A M J
authors.initials: DA
authors.lastname: Theuns
authors.forename: M F
authors.initials: MF
authors.lastname: Scholten
authors.forename: L J
authors.initials: LJ
authors.lastname: Jordaens
mesh_terms: D006328:Cardiac Catheterization / Q000295:instrumentation*; D017115:Catheter Ablation / Q000295:instrumentation*; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000601:surgery*; D016896:Treatment Outcome