title: Tissue voltage discordance during tachycardia versus sinus rhythm: implications for catheter ablation.
abstract: BACKGROUND
  Electroanatomic mapping systems are an important tool to identify cardiac chamber voltage and assess channels of slow conduction.
  
  
  OBJECTIVE
  To assess the correlation between electroanatomic mapping voltage maps obtained during macroreentrant tachycardia compared to sinus rhythm (SR) with a contact mapping system.
  
  
  METHODS
  We retrospectively evaluated patients with atrial flutter (AFL) referred for radiofrequency ablation with electroanatomic voltage maps obtained during AFL and SR. The atrium was divided into predetermined segments. Overall atrial and segmental peak-to-peak bipolar voltages in AFL and SR were assessed. To directly compare a region within the same patient, tissue voltage differences during AFL and SR were assessed on the basis of mean voltage difference.
  
  
  RESULTS
  Sixteen patients (87% men) had available voltage maps. Eighty-one percent had typical cavotricuspid isthmus-dependent right AFL. A mean of 441.7±153.9 vs 398.1±125.4 total points (P = .22) were sampled during AFL and SR, with a mean of 99.5±58.9 vs 91.2±60.4 points (P = .45) sampled per region. Overall right atrial mean voltage was significantly higher during AFL than SR (0.554±0.092mV vs 0.473±0.079mV; P≤.001), with the lateral wall (0.707±0.120mV vs 0.573±0.097mV; P = .0004) and the cavotricuspid isthmus (0.559±0.100mV vs 0.356±0.066mV; P<.0001) also showing higher mean voltage during AFL. When compared within an individual patient, 19% (14 of 75) of the patient regions had a>0.5mV mean voltage difference and 40% (30 of 75) had a>0.25mV mean voltage difference.
  
  
  CONCLUSIONS
  These data suggest that voltage maps performed during macroreentrant atrial arrhythmias often vary significantly from maps obtained during SR.
authors: UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1679, USA. jbradfield@mednet.ucla.edu
authors: Jason S
authors: JS
authors: Bradfield
authors: William
authors: W
authors: Huang
authors: Roderick
authors: R
authors: Tung
authors: Eric
authors: E
authors: Buch
authors: Jean-Phillip
authors: JP
authors: Okhovat
authors: Osamu
authors: O
authors: Fujimura
authors: Noel G
authors: NG
authors: Boyle
authors: Jeffrey
authors: J
authors: Gornbein
authors: Kenneth A
authors: KA
authors: Ellenbogen
authors: Kalyanam
authors: K
authors: Shivkumar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013610:Tachycardia / Q000503:physiopathology* / Q000601:surgery*