TGF beta1 Expression and Atrial MyocardiumFibrosis Increase in Atriai Fibrillation Secondary to Rheumatic Heart Disease

摘要

Background; Atrial fibrosis was considered a structural basis for the development and sustaining of atriai fibrillation (AF), Transforming growth factor-fit (TGF-pi) was one of the main factors for accelerating collagen production. The contribution of TGF-beta1 in the pathogenesis of AF needs further investigation. Hypothesis: The altered expression and distribution of TGF-beta1 will be associated with the changes in atrial fibrosis in different types of AF patients with rheumatic heart disease (RHD).Methods: Right atrial specimens obtained from 38 RHD patients undergoing mitral valve replacement surgery were divided into 3 groups: the sinus rhythm group (n = 8), the paroxysmal AF group (pAF; n = 10), and the chronic AF group (cAF; AF lasting >6 mo; n = 20), The degree of atrial fibrosis, collagen content, serum levels, messenger RNA (mRNA), and protein expression of TGF-pi were detected.Results: The collagen content, serum level, TGFbeta1 rnRNA, and protein expression of the atrial tissue increased gradually in sinus rhythm, for both pAF and cAF groups, respectively. A positive correlation between TGF-beta1 and the degree of atrial fibrosis was also demonstrated (P < 0.05).Conclusion: The TGF-pi expression in atrial tissue increased gradually in proportion to the degree of atrial fibrosis in AF and was associated with the type of AF, which suggests that TGF-fii is possibly involved in the pathogenesis of AF inRHD patients