title: Electro-anatomic mapping of the right atrium: anatomic abnormality is an important substrate.
abstract: OBJECTIVE
  To map and compare the right atrium in patients with AF to those with atrioventricular nodal reentrant tachycardias (AVNRT, as control group) and to investigate the anatomical and electrophysiological abnormality of the right atrium in AF.
  
  
  METHODS
  The anatomy and electrophysiology of right atrium and cavotricuspid isthmus were evaluated in 20 patients with AF (16 M/4 F, mean age 55.9 +/- 10.68 years) and 26 patients with AVNRT (9 M/17 F, mean age 47.50 +/- 19.56 years) during coronary sinus pacing at 600 ms prior to ablation with electro-anatomical mapping system. Right atrial volume (RAV), the length and width of cavotricuspid isthmus (IsL, IsW), unipolar and bipolar voltage in the right atrium (UniV-RA, BiV-RA) were measured and compared between patients with AF and those with AVNRT.
  
  
  RESULTS
  RAV, IsL, IsW, UniV-RA, and BiV-RA were 143.22 +/- 40.72 vs 104.35 +/- 21.06 ml, 39.31 +/- 8.10 vs 32.42 +/- 9.77 mm, 30.54 +/- 7.48 vs 23.15 +/- 6.61 mm, 1.96 +/- 1.24 vs 1.53 +/- 0.91 mv and 1.47 +/- 1.47 vs 1.29 +/- 1.12 mv in AF and AVNRT respectively.
  
  
  CONCLUSIONS
  The right atrial volume is larger; both the length and width of cavotricuspid isthmus are greater. Unipolar and bipolar voltages in the right atrium are higher in AF than in AVNRT, suggesting that the enlarged right atrium, increased length and width of cavotricuspid isthmus, and concomitant atrial hypertrophy are important substrates for initiation and perpetuation of typical AF.
authors.affiliation: Department of Cardiology, Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing 100037, China.
authors.forename: Pihua
authors.initials: P
authors.lastname: Fang
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Radtke
authors.forename: Tony W
authors.initials: TW
authors.lastname: Simmons
authors.forename: Wesley K
authors.initials: WK
authors.lastname: Haisty
authors.forename: Karthik
authors.initials: K
authors.lastname: Ramaswamy
authors.forename: David M
authors.initials: DM
authors.lastname: Fitzgerald
mesh_terms: D000328:Adult; D000368:Aged; D001282:Atrial Flutter / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D006332:Cardiomegaly / Q000150:complications; D005260:Female; D006325:Heart Atria / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000473:pathology* / Q000503:physiopathology