title: Magnetic guidance system for cardiac electrophysiology: a prospective trial of safety and efficacy in humans.
abstract: OBJECTIVE
  We evaluated in humans the safety and efficacy of a novel magnetic guidance system (MGS) for electrophysiological mapping, pacing, and ablation.
  
  
  BACKGROUND
  Catheter ablation of atrial fibrillation and other complex arrhythmias requires precise catheter manipulation and stabilization. We have shown in animals that the MGS can precisely manipulate a mapping catheter within the heart with an external magnetic field rather than manual catheter control.
  
  
  METHODS
  Thirty-one adults referred for diagnostic electrophysiology studies were enrolled in a prospective trial of the MGS. The magnetic catheter was navigated to preselected sites in the right atrium (RA) and right ventricle (RV) in the first 20 patients. Electrograms were recorded at each target site, and pacing thresholds were measured. In a subset of five patients, RA and RV electrograms and stimulation thresholds were recorded with both a standard ablation catheter and the magnetic catheter. Eleven additional patients were recruited for supraventricular tachycardia (SVT) mapping, and seven of these underwent ablation.
  
  
  RESULTS
  Navigation was successful in 200 of 202 predetermined right-sided navigation targets and 13 of 13 targets in the left atria. Pacing thresholds and electrogram amplitudes in the RA and RV were not significantly different between the standard and magnetic catheters. The SVT mapping with the magnetic catheter was successful in 13 patients, including 4 with left-sided accessory pathways. The MGS was used for successful ablation of SVT in seven of seven patients. There were no procedural complications.
  
  
  CONCLUSIONS
  These results demonstrate that the MGS can be used for intracardiac mapping, pacing, and ablation safely and effectively.
authors.affiliation: Washington University School of Medicine, St. Louis, Missouri, USA. MitchNF@pol.net
authors.forename: Mitchell N
authors.initials: MN
authors.lastname: Faddis
authors.forename: Jane
authors.initials: J
authors.lastname: Chen
authors.forename: Judy
authors.initials: J
authors.lastname: Osborn
authors.forename: Michael
authors.initials: M
authors.lastname: Talcott
authors.forename: Michael E
authors.initials: ME
authors.lastname: Cain
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Lindsay
mesh_terms: D000328:Adult; D016275:Atrial Function; D018780:Body Surface Potential Mapping / Q000379:methods*; D006328:Cardiac Catheterization; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006801:Humans; D008280:Magnetics / Q000627:therapeutic use*; D011446:Prospective Studies; D012449:Safety; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome