title: Initial clinical experience of remote magnetic navigation system for catheter mapping and ablation of supraventricular tachycardias.
abstract: BACKGROUND
  A remote magnetic navigation system (MNS) has been developed for mapping and catheter ablation of cardiac arrhythmias. The present study evaluates the safety and feasibility of this system to perform radiofrequency (RF) ablation in patients with supraventricular tachycardias (SVT).
  
  
  METHODS
  A total of 32 patients (22 female; mean age 44 +/- 16 years) with documented SVT underwent mapping and ablation using Helios II (a 4-mm-tip magnetic catheter), under the guidance of the MNS (Niobe II, Stereotaxis, Inc.).
  
  
  RESULTS
  Catheter ablation procedure with MNS was successful in 30/32 (94%) patients including all patients (27/27, 100%) with atrioventricular nodal reentrant tachycardia (AVNRT) and three of five patients (60%) with atrioventricular reentrant tachycardia (AVRT) without any complication. The procedural successful rate in patients with AVNRT was significantly higher than those in patients with AVRT (P < 0.001). Overall, the medium number of RF application using the MNS was 2 (mean 2.7 +/- 1.6, range 1 to 7), and the medium numbers of RF for AVNRT and AVRT were 2 and 3, respectively. There was no significant difference in the mean procedural time between patients with AVNRT and AVRT (126.3 +/- 38.6 vs. 138.0 +/- 40.3 min, P = 0.54). However, the mean fluoroscopy time was significantly shorter in patients with AVNRT than those with AVRT (5.7 +/- 3.0 vs. 16.5 +/- 2.5 min, P < 0.001). Among those patients with AVNRT, the mean procedural time (139.3 +/- 45.0 vs. 112.3 +/- 24.9 min, P = 0.07) and fluoroscopic time (3.2 +/- 1.0 vs. 8.0 +/- 2.2 min, P < 0.001) were shorter for the later 13 patients than the first 14 patients, suggesting a learning curve in using the MNS for RF ablation.
  
  
  CONCLUSIONS
  The Niobe MNS is a new technique that can allow safe and effective remote-controlled navigation and minimize the need for fluoroscopic guidance for ablation catheter of AVNRT. However, further improvement is required to achieve a higher successful rate for treatment of AVRT.
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Dongjie
authors.initials: D
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Qijun
authors.initials: Q
authors.lastname: Shan
authors.forename: Jiangang
authors.initials: J
authors.lastname: Zou
authors.forename: Minglong
authors.initials: M
authors.lastname: Chen
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Hou
authors.forename: Fengxiang
authors.initials: F
authors.lastname: Zhang
authors.forename: Wen-Qi
authors.initials: WQ
authors.lastname: Li
authors.forename: Kejiang
authors.initials: K
authors.lastname: Cao
authors.forename: Hung-Fat
authors.initials: HF
authors.lastname: Tse
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping / Q000295:instrumentation / Q000379:methods*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008280:Magnetics / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult