Atrial fibrillation (AF) is the most common arrhythmia complicating cardiac surgery. Patients who develop AF following cardiac surgery are at increased risk of stroke, congestive heart failure, and haemodynamic instability. Postoperative AF is invariably associated with increased intensive care unit stays and prolonged hospitalisations and is responsible for significant patient morbidity and health care expenditures. Management of AF after cardiac surgery can be guided by knowledge of what is known about clinical postoperative AF and the evidence available on the efficacy of treatment strategies. The following is a concise review of postoperative AF as well as an evidence based approach to the management of AF after cardiac surgery.

PREVALENCE

Postoperative AF occurs in approximately 30–40% of patients undergoing coronary artery bypass grafting (CABG) surgery and in as many as 64% of patients with concomitant valve surgery. In a prospective observational study of 4657 patients undergoing CABG surgery at 70 centres, the peak incidence of AF occurred on postoperative day 2 and 3. Over 60% of AF episodes occurred by day 2. Fifty-seven per cent of patients had only one episode of AF during their hospitalisation.1

CLINICAL RISK FACTORS

Several clinical factors have been implicated as risk factors for postoperative AF (box 1). These risk factors include advanced age, concomitant valve surgery, a prior history of AF, congestive heart failure, left atrial enlargement, decreased left ventricular function, postoperative withdrawal of β-adrenergic blockade, chronic obstructive pulmonary disease, and P wave duration on a 12 lead ECG. Among these risk factors, age is the most consistently reproduced independent risk factor for postoperative AF. In a study of patients undergoing CABG, Zaman et al reported that only 3.4% of patients aged 50–54 years developed postoperative AF, compared to 42.2% of patients aged 70–74 years. The odds of developing AF increased 1.48-fold for each 5 year increase in …