Objective To investigate the efficacy of losartan combined with amiodarone in cardioversion of atrial fibrillation(AF)and maint of sinus rhythm in patients with paroxysmal AF.Methods From January 2003 to October 2005,a total of 86 consecutive patients with paroxysmal AF in 421 Hospital of PLA were randomly dividid into two group:group A(amiodarone,n=44)and.group B(amiodarone plus losartan n=42).The conversion of atrial fibrillation in 24 h,3 d and 7 d after therapy was investigated.The left atrial diameter was measured with transthoracic echocardiogram at before and after 6,12-months of treatment andyzed up to 12 months.Results The rate of cardioversion of AF is significantly higher in group A than group B at 7 d(86.36% vs 95.23%,P