Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia seen in clinical practice. The incidence of AF increases significantly with advancing age, with the prevalence being 8% for population of age 80 and above. 1 For those who are 40 years and older, the lifetime risk for the development of AF is 1 in 4 in both men and women. 2,3 With an ageing population, an increase in the incidence and prevalence of AF has been reported worldwide. 4,5 Indeed, AF has become such a common problem that it is now described as 'a major epidemic' .Due to the close relationship between AF, stroke and thromboembolism there has been a need for increased caution. Irrespective of applying a rate-control or rhythm-control strategy thromboprophylaxis remains the essential core of any AF management strategy. Given that AF is so common various management guidelines have been published over the last few years. 6,7 In the UK, the evidence-based national guidelines for the management of AF were published by the National Institute for Health and Clinical Excellence (NICE) in June 2006. 7 The methodology for the NICE guidelines differs from other expert consensus-based guidelines in that, following agreement and definition of a scope for the NICE guideline, pertinent questions on AF management are formulated and a formal systematic review undertaken by an information scientist who would retrieve, assess and organise sources of published evidence. The latter is then critically appraised and graded by a health service research fellow and, if needed, a health economist. The synthesised evidence is reviewed and debated by a guideline development group (GDG), which included multidisciplinary representatives from various learned bodies and specialist organisations.Despite the published guidelines for the management of AF, this common arrhythmia remains poorly managed, both in primary and secondary care, with marked variation in the approach to investigation and treatment. Apart from the specific recommendations, the NICE guidelines have highlighted five key priorities for implementation as well as audit criteria and areas for future research (Box 1). The remit of the NICE guideline on AF management was to provide a practical, pragmatic and highly applicable national guideline to the UK clinical setting, which would be applicable for Ͼ80% of AF patients for Ͼ80% of the time. Given this aim, has the publication of these guidelines actually improved AF management?In the current issue of Clinical Medicine, the paper by Loo and colleagues examines existing clinical practice in advance of publication of the NICE guidelines. 8 Their study suggests that only 84% of 131 patients with diagnosis of AF had either electrocardiogram (ECG) documentation in primary and/or secondary care. Almost half of the patients with AF were managed in primary care alone and the diagnosis of AF was generally accurate. The use of echocardiography is an important part of management, and in the paper by Loo et al only 44% of the study population underwent an echocar...