 The prevalence of atrial fibrillation AF has increased in recent years. The construction and function of right atrium havent shown clearly before and after radiofrequency ablation RFCA.The purpose of the study is to investigate whether RFCA can lead to inverse reconstruction of right atrium for atrial fibrillation patients, which diagnosing by speckle tracking echocardiography combined with real-time three dimensional echocardiography. All patients will be followed up for 12 months. 