The Study Of Endothelin System And Myocardial Fibrosis With Atrial Fibrillation

Objective: Atrial fibrillation(AF) is the most common arrhythmia with the increased risk of stroke,congestive heart failure and mortality. Atrial remodeling is the pathogensis that is generally acknowledged. Atrial remodeling includes electrical remodeling, systolic remodeling and structural remodeling. Endothelin system plays an important role in electrical remodeling, myocardial fibrosis plays an important role in structural remodeling. The present study aimed to determin mRNA levels of the endothelin system and the serum levels of myocardial fibrosis markers in patients with AF, and to explore the molecule mechanisms of atrial electrical remodeling and atrial structural remodeling.Methods: The right atrial tissue samples were taken from 25 patients with cardiac surgery. 10 patients were in sinus rhythm. 10 patients had persistent AF and 5 patients had paroxysmal AF. The mRNA amounts of pro-endothelin- 1, endothelin receptor A and endothelin receptor B were studied by Real-time Fluorescence Quantitative PCR(FQ-PCR) method. The concentrations of serum procollagen type I (PC I ) and procollagen type III (PC III) were measured by enzyme linked immunosorbent assay(ELISA) in 70 patients of AF and 70 controls. The datas were analyzed by SPSS 11.5.Result: (1)The mRNA amounts of pro-endothelin-1 significantly increased in both paroxysmal AF and persistent AF groups compared with the sinus rhythm group(P<0.05, P<0.05). The significant difference in pro-endothelin-1 was also observed between the persistent AF and paroxysmal AF groups(P<0.05). (2) The mRNA amounts of endothelin receptor A and endothelin receptor B significantly reduced in both paroxysmal AF and persistent AF groups compared with the sinus rhythm group(P<0.05, P<0.05). The significant difference in endothelin receptor A and endothelin receptor B was also observed between the persistent AF and paroxysmal AF groups(P<0.05). (3)Compared with controls, the concentrations of serum PC I and PCIII were significantly increased in patients with AF.Conclusion: The change of expression of endothelin system in patients with atrial fibrillation was possibly one of the molecule mechanisms of atrial electrical remodeling and related with the genesis and maintenance of atrial fibrillation. The levels of serum myocardial fibrosis markers increased in patients with AF. These results indicated that fibrosis may take place in atrial interstitium of the patients.