This study is aimed to compare the efficacy of bi-atrial ablation with left atrial ablation for atrial fibrillation during mitral valve surgery in patients with rheumatic mitral valve disease.

Atrial fibrillation (AF) is present in 40%-60% of patients with rheumatic mitral valve disease (RMVD), which is an independent predictor of mortality and late stroke. During mitral valve (MV) surgery, the open left atrium facilitates a bi-atrial ablation procedure. However, a simplified lesion set including isolated pulmonary vein isolation or posterior left atrial (LA) wall isolation or LA maze was usually applied. The current literatures provide insufficient evidence to determine the potential benefits of bi-atrial ablation procedure when comparing with LA ablation procrdure in patients with non-paroxysmal AF and RMVD.

Patients with RMVD often have longer history, which tends to affect the right atrium, including pulmonary hypertension or tricuspid regurgitation.The necessity of bi-atrial ablation procedure targeting the bi-atrial substrate for AF in RMVD requires to be explored. In this study, we aimed to compare the efficacy of bi-atrial ablation with LA ablation for AF during MV surgery in patients with RMVD.

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosis of persistent atrial fibrillation(AF) or long-standing persistent AF by medical history and Holter monitoring (persistent AF lasting more than 7 days; long-standing persistent AF lasting more than 1 year).
• Rheumatic mitral valve disease(RMVD) requires mitral valve surgery( RMVD was determined by history of acute rheumatic fever, valve morphology, echocardiographic findings and pathological diagnosis).
• Consent to surgical ablation of AF

Exclusion Criteria:

• Paroxysmal AF
• Degenerative or ischemic mitral valve disease
• Evidence of active infection
• Previous catheter ablation or surgical ablation for AF
• Surgical management of hypertrophic obstructive cardiomyopathy
• Absolute contraindications for anticoagulation therapy
• Left atrial thrombosis (not including left atrial appendage thrombosis alone)
• Chronic obstructive pulmonary disease(Forced expiratory volume in 1 second (FEV1)<30% anticipated value)
• Uncontrolled hypo- or hyperthyroidism
• Mental impairment or other conditions that may not allow participants to understand the nature, significance, and scope of study
• Left atrial diameter>70mm
• Right ventricular dysfunction (TAPSE<16) or moderate to severe tricuspid regurgitation or pulmonary artery pressure (estimated by echocardiography) >60mmHg
• Coronary artery bypass grafting is required for participants with coronary heart disease
• Previous cardiac surgery
• Refuse to participate in this study