Atrial fibrillation is the most common arrhythmia after cardiac surgery.The patients undergoing valve surgery or combined valve and CABG surgery have higher incidence of postoperative AF than patients having alone CABG.Atrial fibrillation is especially common after mitral valve surgery, occurring in as many as 64% of patients.Aetiology of atrial fibrillation after cardiac surgery is multifactorial.Even atrial fibrillation after cardiac surgery is self limiting in most cases but even when it is uncomplicated, its treatment requires additional medical treatment and a prolonged hospital stay and it subsequently increases the costs of operative treatment.In some cases atrial fibrillation can cause haemodynamic compromise and increase the risk of stroke.