title: Remote magnetic navigation system provides a superior catheter stability in acquisition of His bundle electrogram.
abstract: BACKGROUND
  Catheter stability is a key prerequisite for a successful EP procedure. Remote magnetic navigation system (RMNS) was recently introduced for the manipulation of EP catheters. It may provide an improved catheter stability but this has not been tested prospectively. We performed a prospective cross-over study which compares the amplitude and stability of the His-electrogram obtained by catheters using RMNS vs conventional manual catheter placement.
  
  
  METHODS
  His-electrograms were continuously recorded for 3 min with a conventional His mapping catheter and magnetically tipped catheter capable of alignment in the direction of an externally controlled magnetic field (0.08-0.1 Tesla) in the same patient. First 100 beats of each recording were used for data analysis. The amplitudes of each set of His-electrograms were measured and compared in microvolts. Coefficient of variation of the measured His-signal amplitude was calculated for each beat. Miller's test for the equality of the coefficients of variation and Levene's test of homogeneity of variance were used for statistical analysis.
  
  
  RESULTS
  Fourteen patients (6 males; aged 48+/-25 years) were included in the study. His-electrograms were more stable and homogenous with RMNS than manual method in 10/14 patients. Pooled variance of all RMNS recordings was significantly less than pooled variance of manual recordings (p=0.01).
  
  
  CONCLUSIONS
  His-electrogram recording using RMNS is more stable and homogeneous than traditional manual method in most patients. These data indicate a superior catheter stability with RMNS.
authors: Caritas St. Elizabeth's Medical Center of Boston, Tufts University School of Medicine, and Division of Aging, Brigham and Women's Hospital, Boston, MA 02111, USA. stahir@tufts-nemc.org
authors: Syed Muhammad Ali
authors: SM
authors: Tahir
authors: G Muqtada
authors: GM
authors: Chaudhry
authors: Muhammad Ali
authors: MA
authors: Syed
authors: Thomas
authors: T
authors: Marchese
authors: Gregory
authors: G
authors: Kotler
authors: Charles I
authors: CI
authors: Haffajee
authors: Michael V
authors: MV
authors: Orlov
mesh_terms: D002036:Bundle of His; D006328:Cardiac Catheterization / Q000295:instrumentation*; D018592:Cross-Over Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016014:Linear Models; D008280:Magnetics / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013238:Stereotaxic Techniques / Q000295:instrumentation; D013617:Tachycardia, Supraventricular / Q000503:physiopathology*