NANETTE KASS WENGER, MD: When the upper chambers of the heart, the atria, fibrillate, it means that they don't have coordinated pumping function. They simply quiver, like a bowlful of Jello. And because of that, the blood may clot in the corners of those atria.
Now, those blood clots may go anywhere—to the lung, to the brain, to the body. And atrial fibrillation is one of the most common causes of stroke, with its disastrous consequences. So the older you are, the more likely you are to have stroke from atrial fibrillation. But younger patients are not truly protected, so that warfarin, the blood thinner, is absolutely necessary to prevent clots forming in the atrium and those clots going to the lung and all over the body.
ADOLPH M. HUTTER, JR., MD: The point is that everybody in atrial fibrillation has to be protected from a stroke. Warfarin is a very good drug to do it. However, many patients get equal protection from aspirin, 325 mg. Not a baby aspirin, a regular adult aspirin. And we can identify by certain risk factors which form of therapy is better for you.