Atrial fibrillation (AF) is connected with an increased morbidity and mortality. In addition, quality of life is diminished due to palpitations, dyspnea, dizziness and syncope. AF is frequently associated with valvular and coronary disease. In the AF patients undergoing valvular or coronary surgery the arrhythmia almost always relapses. For symptom control anti-arrhythmic drugs and cardioversion are used but breakthrough arrhythmias and side effects of the drugs happen frequently. For more effective symptom control "add-on" arrhythmia surgery is being advocated. However, at present the investigators do not know whether add-on arrhythmia surgery indeed affects morbidity and quality of life.

The hypothesis being studied is that add-on arrhythmia surgery in patients with AF undergoing valvular or coronary surgery improves quality of life, establishes chronic sinus rhythm and reduces perioperative and long-term morbidity associated with AF.

Multicentre prospective parallel randomised controlled trial. In total 150 patients with documented atrial fibrillation (chronic and paroxysmal), were randomly assigned by a central computer system to undergo cardiac surgery with add-on surgery or without. This assignment was blinded to patients and all medical personnel except for the surgical team during total follow up. Patients completed quality of life questionnaires, comprising the RAND 36-item Health Survey 1.0 (SF-36), Multidimensional Fatigue Inventory-20 (MFI-20) and EuroQoL (EQ-5D and VAS) at baseline and 3, 6 and 12 months following operation.

Inclusion Criteria:

• Patients undergo valvular surgery and/ or coronary surgery,
• All patients have documented chronic atrial fibrillation of paroxysmal atrial fibrillation.
• Patients have given written informed consent.

Exclusion Criteria:

• Patients who do not speak Dutch or can not read Dutch.
• Patients with a Sick Sinus Syndrome.
• Patients with contraindications for oral anticoagulant agents.
• Incompetent to act for oneself