The Link Between Atrial Fibrillation and Stroke
Did you know that
atrial fibrillation (AFib) is linked to a higher risk of
AFib can cause a stroke because the heart's atrium does not contract properly. As a result, blood moves slowly, pooling and clotting in the left atrium. When blood clots form, the change in heart rhythm can cause them to travel to the brain or elsewhere, resulting in stroke.
"People with AFib-who experience irregular and/or rapid heartbeat episodes-have a five- to 17-fold increased incidence of stroke compared to people without AFib," says
Dr. Charles Haffajee, a cardiac electrophysiologist and director of device trials and the electrophysiology network at BIDMC's CardioVascular Institute.
"One of the goals of treating AFib is to reduce the risk of stroke. Most AFib patients take a blood thinner like
Coumadin®, which can reduce risk of stroke to about one percent a year," according to Dr. Haffajee.
Strokes caused by AFib tend to be worse than other strokes. Half of all strokes due to AFib are major and disabling and are fatal 23 percent of the time.
Some patients with AFib have "mini-strokes" (called TIAs or
transient ischemic attacks). These don't cause lasting damage, but are a warning sign.
"About 35 percent of patients with AFib will suffer a stroke if the condition is left untreated," says Dr. Haffajee. "Unfortunately, many AFib patients who should be taking a blood thinner are not."
This problem may be lessened when a new type of blood thinner, known as a direct thrombin inhibitor, becomes available. The U.S. Food & Drug Administration is expected to approve the first of these alternatives, dabigatran, in early 2011. This new treatment should be easier to take, since-unlike Coumadin-it doesn't require regular blood tests to manage dosage and is not affected by green vegetables or antibiotics.