TY - JOUR T1 - Atrial fibrillation: classification, pathophysiology, mechanisms and drug treatment JF - Heart JO - Heart SP - 939 LP - 943 DO - 10.1136/heart.89.8.939 VL - 89 IS - 8 AU - Vias Markides AU - Richard J Schilling Y1 - 2003/08/01 UR - http://heart.bmj.com/content/89/8/939.abstract N2 - The prevalence of atrial fibrillation (AF), already the most common sustained cardiac arrhythmia, is constantly rising, even after adjusting for age and presence of structural heart disease. AF increases the risk of stroke sixfold and is associated with a twofold increase in mortality, which remains above 1.5-fold after adjusting for co-morbidity, predominantly caused by cerebrovascular events, progressive ventricular dysfunction, and increased coronary mortality. The adverse haemodynamic effects of AF are well described and relate not only to loss of atrial contraction, but also to the accompanying rapidity and irregularity of ventricular contraction. Although AF may be asymptomatic, up to two thirds of patients report that the arrhythmia is disruptive to their lives. Finally, the treatment of AF and its associated complications creates a significant and increasing economic burden. This article focuses predominantly on the pathophysiology of the arrhythmia and its pharmacological treatment. Anticoagulation for prevention of thromboembolism, a fundamental principle in the management of this arrhythmia, electrical cardioversion, percutaneous ablation techniques, and surgery for AF are not discussed in any detail. AF may be classified based on aetiology, depending on whether it occurs without identifiable aetiology in patients with a structurally normal heart (lone AF), or whether it complicates hypertensive, valvar, or other structural heart disease. A classification system based on the temporal pattern of the arrhythmia has been recently recommended.1 Patients presenting to medical attention may have a first detected episode of AF or, if previous episodes have been documented, recurrent arrhythmia. Episodes themselves may be paroxysmal, if they terminate spontaneously, usually within seven days, or persistent if the arrhythmia continues requiring electrical or pharmacological cardioversion for termination. AF that cannot be successfully terminated by cardioversion, and longstanding (> 1 year) AF, where cardioversion is not indicated or has not been attempted, is termed permanent (fig 1). … ER -