风心病慢性房颤心房连接蛋白表达与AERP的相关性研究

目的:通过检测风心病慢性房颤患者左、右心房缝隙连接蛋白Cx40和Cx43表达及相应部位的心房有效不应期(AERP)研究两者之间的相关性,探讨Cx40和Cx43对慢性房颤左、右心房电生理特性的影响. 方法:29例风心病伴或不伴慢性房颤的患者,共分2组:窦性心律组(SR组,n=13),慢性房颤组(CAF组,n=16),另取6例非风心病作为正常对照组.在行二尖瓣置换术时,采用心外膜标测技术测定左、右心房的AERP,并在相应部位切取心房组织,通过Western印迹法检测左、右心房肌Cx40和Cx43的表达,同时对两者行相关性分析. 结果:CAF组患者左、右心房Cx40的表达和AERP较SR组有明显下降(P<0.05),而Cx43无明显变化;左心房后壁Cx40的相对表达量与AERP呈明显正相关(r＝0.762,P<0.01),而Cx43与AERP无明显相关.SR组中,Cx40和Cx43均与AERP无明显相关.结论:在风心病慢性房颤心房中,Cx40表达下调参与慢性房颤的心房重构,并影响心房的电生理特性,提示Cx40的表达对风心病慢性房颤的发生和维持具有重要的作用.

Correlation of Cx40 and Cx43 expression with electrophysiological characteristics of atrium in atrial fibrillation of patients with rheumatic heart disease

Objective:To investigate Cx40 and Cx43 expressions of atria in patients with rheumatic heart diseases and chronic atrial fibrillation and their relationship with correspondent atrial effective refractory period(AERP) for elucidating effects of Cx40 and Cx43 on electrophysiologic characters. Methods: Epicardial mapping for AERP was performed in 29 patients with or without atrial fibrillation before mitral replacement during operation. Correspondent atrial myocardial specimens were acquired for detecting Cx40 and Cx43 expression and location with Western blot. Correlative study were conducted between Cx40 and Cx43 expression and electrophysiologic characters. Results: Atria Cx40 expression and AERP in CAF group decreased significantly compared with those in SR group(P<0.05), while Cx43 had no obvious changes. Cx40 expression in the posterior wall of left atrium was positively correlated with AERP (r=0.762, P<0.01), while Cx43 expression had no relation with AERP. In SR group, neither Cx40 nor Cx43 had correlation with AERP.Conclusion: Downregulation of Cx40 expression participates in atrial reconstruction of chronic atrial fibrillation and has an effect on electrophysiologic characters in rheumatic heart diseases with chronic atrial fibrillation. Changes of Cx40 expression play an important role in origin and development of chronic atrial fibrillation in rheumatic heart diseases.