Atrial Fibrillation As A Risk Factor For Stroke

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, occurring in 1–2% of the general population. AF confers a 5-fold risk of stroke, and one in five of all strokes is attributed to this arrhythmia. Ischemic strokes in association with AF are oft en fatal, and those patients who survive are left more disabled by their stroke and more likely to suffer a recurrence than patients with other causes of stroke. The prevalence of AF increases with age. Men are more oft en affected than women. AF is associated with a variety of cardiovascular conditions: valvular heart diseases, cardiomyopathies, including primary electrical cardiac diseases, which carry an increased risk for AF, especially in young patients. Atrial septal defect is associated with AF in 10–15%. This association has important clinical implications for the antithrombotic management of patients with a previous stroke or transient ischemic attack (TIA) and an atrial septal defect. AF may manifest initially as an ischemic stroke or TIA, and it is reasonable to assume that most patients experience asymptomatic, oft en self-terminating, episodes of arrhythmia, before AF is first diagnosed. Most patients with acute AF will require anticoagulation unless they are at low risk of thromboembolic complications (no stroke risk factors) and no cardioversion is necessary. Much earlier detection of the arrhythmia might allow the timely introduction of therapies to protect the patient, not only from the consequences of the arrhythmia, but also from progression of AF from an easily treated condition to an utterly refractory problem.