Introduction to Atrial Fibrillation

Risk of Stroke in Atrial Fibrillation

Previously thought to be an insignificant arrhythmia, the potential complications of atrial fibrillation (AF) have just been recognized in the past few years. The irregular beating of the atrial chambers that is characteristic of atrial fibrillation results in stagnation and pooling of blood in the heart that can lead to blood clot formation, particularly in the left atrium. These blood clots can travel via the circulatory system and lodge in the brain, thereby, cutting-off the blood supply to a region of the brain (stroke). In fact, stroke represents the most common devastating consequence of atrial fibrillation.

Atrial fibrillation is recognized as an independent risk factor for stroke and patients with atrial fibrillation are about 5-times more likely to suffer a stroke than people without atrial fibrillation. Other factors that increase the risk of stroke in people with atrial fibrillation include:

• History of previous stroke or "mini-strokes" known as transient ischemic attacks (TIAs)
• Hypertension (high blood pressure)
• Congestive heart failure
• Advancing age (particularly age 75 or older)
• Coronary artery disease
• Diabetes

Based on the presence or absence of these risk factors, doctors can better determine which patients with atrial fibrillation are at high risk for stroke and initiate appropriate treatment with anticoagulant medications to reduce the likelihood of a stroke.