title: Decreased connexin 43 and increased fibrosis in atrial regions susceptible to complex fractionated atrial electrograms.
abstract: OBJECTIVE
  Complex fractionated atrial electrograms (CFAE) is distributed at preferential sites of atrium, and the mechanism underlying CFAE is not fully understood. We hypothesized that preexisting atrial abnormalities may be involved in the formation of CFAE.
  
  
  METHODS
  Twelve pigs were subjected to acetylcholine infusion and right atrial pacing to induce sustained atrial fibrillation. The shortest complex interval map was used to visualize CFAE on three-dimensional anatomic structure of left atrium, and the CFAE sites were labeled by ablation. The expression of connexin 43 (Cx43) and myocardial fibrosis were examined.
  
  
  RESULTS
  The expression of Cx43 at CFAE sites was significantly decreased when compared with non-CFAE sites, while myocardial fibrosis was enhanced in CFAE sites compared with non-CFAE sites.
  
  
  CONCLUSIONS
  These results suggested that the decreased expression of Cx43 and enhanced myocardial fibrosis at CFAE sites of the left atrium may be the structure abnormalities underlying CFAE.
authors.affiliation: Department of Cardiology, Shanghai Chest Hospital Affiliated to Shanghai Jiaotong University, 241 West Huaihai Road, Shanghai 200030, China. xkliuxu@126.com
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.forename: Hai-feng
authors.initials: HF
authors.lastname: Shi
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Tan
authors.forename: Xin-hua
authors.initials: XH
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.forename: Jia-ning
authors.initials: JN
authors.lastname: Gu