Objectives:To explore possible mechanisms of connexin40(Cx40)remodeling by detecting Cx40 mRNA expression of the crista terminalis and left atrium(LA)in patients with rheumatic heart disease(RHD)associated chronic atrial fibrillation(AF).Methods:Twenty patients were enrolled in this study,who underwent surgical operation for RHD-associated mitral disease,including 10 with sinus rhythms(rhythm group)and 10 with AF(AF group).Another 6 patients with non-RHD sinus rhythms were divided into the control group.A small amount of myocardial tissue was cut from the crista terminalis and the LA posterior wall during the valvular replacement operation.Cx40 mRNA expression was assayed by real-time fluorescent quantitation polymerase chain reaction (RT-PCR).Results:There was no significant difference in Cx40 mRNA expression in the crista terminalis and LA posterior wall between the 3 groups,and there was no significant difference in Cx40 mRNA expression between the crista terminalis and LA within each group.Conclusion:Based on the finding in previous studies that there existed evident remodeling of atrial Cx40 protein in patients with chronic RHD,the results of the present study suggest that the mechanism of Cx40 remodeling probably lies in the post transcriptional level. Objectives: To explore the possible mechanisms of connexin40 (Cx40) remodeling by detecting Cx40 mRNA expression of the crista terminalis and left atrium (LA) in patients with rheumatic heart disease (RHD) associated chronic atrial fibrillation (AF). Methods: Twenty patients were enrolled in this study, who underwent surgical operation for RHD-associated mitral disease, including 10 with sinus rhythms (rhythm group) and 10 with AF (AF group). Another 6 patients with non-RHD sinus rhythms were divided into control group. A small amount of myocardial tissue was cut from the crista terminalis and the LA posterior wall during the valvular replacement operation. Cx40 mRNA expression was assayed by real-time fluorescent quantitation polymerase chain reaction (RT-PCR). Results: There was no significant difference in Cx40 mRNA expression in the crista terminalis and LA posterior wall between the 3 groups, and there was no significant difference in Cx40 mRNA expression between the crista terminalis and LA within ea ch group. Conflusion: Based on the finding in previous studies that there exists evident remodeling of atrial Cx40 protein in patients with chronic RHD, the results of the present study suggest that the mechanism of Cx40 remodeling probably lies in the post transcriptional level.