An experimental study on the effects of cilazapril and valsartan on atrial structural remodeling in atrial fibrillation dogs / 中国实用内科杂志

ABSTRACT

Objective To investigate the effects of Cilazapril and Valsartan on atrial structural and functional remodeling and its mechanism in atrial fibrillation(AF)dogs induced by chronic rapid atrial pacing.Methods Twenty-seven AF dog models were built by the First Affiliated Hospital of Harbin Medical University from Mar.2006 to Oct.2006.The experimental dogs were randomly divided into sham-operated group(n=6),control group(n=7),Cilazapril group(n=7)and Valsartan group(n=7).The dogs in control group,Cilazapril group and Valsartan group were paced at 400 bpm for 6 weeks.The dogs in Cilazapril and Valsartan group received Cilazapril(1 mg?kg-1?d-1)and Valsartan(30 mg?kg-1?d-1)1 week before rapid atrial pacing until pacing stop respectively.Transthoracic and transoesophageal echocardiographic examinations were performed to detect changes in structure and function of left atrium and left atrial appendage,before and after 6-week rapid atrial pacing.Atrial collagen volume fraction(CVF)was analyzed by Masson staining.The expression of ERK1 and ERK2 in the atrial tissue were tested by immunohistochemistry.TUNEL technique was used to detect the atrial cell apoptosis.Results (1)Compared with the control group,the LA and LAA volumes were significantly smaller,LAEF,LAAEF,V-LAA+ and V-LAA-were dramaticaly higher in the Cilazapril group and the Valsartan group after 6-week rapid atrial pacing.(2)Compared with the control group,the incidence of apoptosis,CVF and the expression of atrial ERK1 and ERK2 decreased dramatically in the Cilazapril group and the Valsartan group.Conclusion Cilazapril and Valsartan could prevent atrial fibrosis and cell apoptosis in the atrial fibrillation dogs induced by chronic rapid atrial pacing.