Decreased connexin 43 and increased fibrosis in atrial regions susceptible to complex fractionated atrial electrograms.
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.
Liu
Xu
X
Department of Cardiology, Shanghai Chest Hospital Affiliated to Shanghai Jiaotong University, 241 West Huaihai Road, Shanghai 200030, China. xkliuxu@126.com
Shi
Hai-feng
HF
Tan
Hong-wei
HW
Wang
Xin-hua
XH
Zhou
Li
L
Gu
Jia-ning
JN