title: Effect of presenting rhythm on image integration to direct catheter ablation of atrial fibrillation.
abstract: BACKGROUND
  Magnetic resonance (MR) imaging of the left atrium (LA) can be integrated with electroanatomic mapping systems to guide catheter ablation of atrial fibrillation (AF). The usefulness of this technique is dependent on the accuracy of image integration.
  
  
  OBJECTIVE
  The aim of this study is to determine the effect of heart rhythm at the time of pre-procedure MR imaging and heart rhythm at the time of ablation on integration error.
  
  
  METHODS
  Fifty-two consecutive patients who underwent catheter ablation for AF were included. All patients underwent MR imaging of LA and pulmonary veins and image integration with real-time electroanatomic mapping. The rhythm at the time of MR imaging and on the day of ablation was recorded. CARTO-Merge software (Biosense-Webster) was used to calculate the average accuracy of integration of electroanatomic points with MR-derived reconstructions.
  
  
  RESULTS
  There was no significant difference in integration error between patients who were in AF at the time of their MR vs. those who were in sinus rhythm at the time of their MR (1.76 +/- 0.26 vs. 1.88 +/- 0.31 mm, p = 0.15). There was also no significant difference in integration error between patients who were in concordant vs. discordant rhythms at the time of MR vs. day of ablation (1.81 +/- 0.23 vs. 1.89 +/- 0.32 mm, p = 0.40). There was a trend toward less integration error between patients who were in AF on the day of ablation vs. those in sinus rhythm (1.74 +/- 0.26 vs. 1.89 +/- 0.31 mm, p = 0.07).
  
  
  CONCLUSIONS
  Image integration can be performed to direct catheter ablation of AF regardless of the rhythm at the time of imaging and ablation.
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Anshul M
authors.initials: AM
authors.lastname: Patel
authors.forename: E Kevin
authors.initials: EK
authors.lastname: Heist
authors.forename: Jianping
authors.initials: J
authors.lastname: Chevalier
authors.forename: Godtfred
authors.initials: G
authors.lastname: Holmvang
authors.forename: Andre
authors.initials: A
authors.lastname: D'Avila
authors.forename: Theofanie
authors.initials: T
authors.lastname: Mela
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Ruskin
authors.forename: Moussa C
authors.initials: MC
authors.lastname: Mansour
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013382:Subtraction Technique; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult