title: Infarct architecture and characteristics on delayed enhanced magnetic resonance imaging and electroanatomic mapping in patients with postinfarction ventricular arrhythmia.
abstract: BACKGROUND
  Delayed enhanced magnetic resonance imaging (DE-MRI) can be used for the exact assessment of myocardial infarct scar. Electroanatomic (EA) mapping can identify the subendocardial extension of infarcts and is used to identify and eliminate areas critical for postinfarction ventricular arrhythmias.
  
  
  OBJECTIVE
  The purpose of this study was to correlate DE-MRI with EA mapping in postinfarction patients with ventricular arrhythmias to assess myocardial infarct architecture and its relationship to postinfarction ventricular arrhythmias.
  
  
  METHODS
  EA mapping during sinus rhythm was performed in 14 postinfarction patients (10 men; age 64 +/- 10 years; ejection fraction 0.33 +/- 0.12) referred for ablation of ventricular arrhythmias. All patients underwent prior DE-MRI. Both DE-MRI and EA mapping data were registered in three-dimensional space. Presence of scar and its transmurality as well as scar core versus gray zone were assessed on DE-MRI and correlated with EA maps; furthermore, the electrogram characteristics of the EA map were correlated with the DE-MRI.
  
  
  RESULTS
  Scar areas as assessed by bipolar and unipolar voltages in the EA map both correlated well with the scar as defined by DE-MRI. The best cutoff value to differentiate subendocardial scar from normal myocardium was 1.0 mV for bipolar voltage and 5.8 mV for unipolar voltage. Areas with DE had distinct electrophysiologic characteristics compared with nonenhancing sites. All identified sites that were critical for postinfarction ventricular tachycardia (31/31) and premature ventricular complexes (5/5) were located within areas of DE, with most (71%) being located in the core area of the scar.
  
  
  CONCLUSIONS
  DE-MRI can accurately predict the EA characteristics of corresponding subendocardial locations. Critical sites of postinfarction arrhythmias were confined to areas of DE. The scar information on MRI can be selectively imported into an EA mapping system to facilitate the mapping and ablation procedure.
authors.affiliation: University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA.
authors.forename: Benoit
authors.initials: B
authors.lastname: Desjardins
authors.forename: Thomas
authors.initials: T
authors.lastname: Crawford
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
mesh_terms: D018780:Body Surface Potential Mapping / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D011379:Prognosis; D012720:Severity of Illness Index; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors