Objective To investigate the protein expression and mRNA expression of Cx40 in crista terminalis of patients suffered from rheumatic heart disease with chronic atrial fibrillation. And evaluate the function of the remodelling of Cx40 in development and maintenance of atrial fibrillation in rheumatic heart disease.

Methods A small piece of myocardial specimen was acquired from crista terminalis during the operation in 20 patients who need operation therapy for rheumatic mitral valve disease and six patients undergoing other cardiac surgery served as control group. Western blot was used to detect expression of Cx40. Cx40 mRNA expression was detected by real-time fluorescence quantitative PCR method.

Results Compared with sinus rhythm, Cx40 expression was decreased in chronic atrial fibrillation. But, the difference of Cx40 mRNA expression among the three groups had no statistical significance.

Conclusion The remodelling of Cx40 plays an important role in the development and maintenance of atrial fibrillation in rheumatic heart disease. And the mechanism of the remodelling of Cx40 remains in the level after transcription of Cx40 gene.