The connection between A-fib and stroke

Parkland Medical Center - June 10, 2021

For atrial fibrillation (AF or A-fib) patients and their loved ones, the connection between A-fib and stroke can be frightening. Stroke is the leading cause of adult disability and the fifth leading cause of death in the United States.

And A-fib can increase a person’s risk of stroke by up to five times. The good news is that there have been some significant advancements in treatment options that can help to substantial lower that risk.

The A-fib and stroke connection

Atrial fibrillation causes poor blood flow in the upper chambers of the heart, called the atria, and allows blood to pool in those chambers. This can allow a blood clot(called a thrombus) to form. If a piece of the clot breaks off, it is then called an embolus, which can enter circulation and may cause a blockage in a small blood vessel. An embolus can travel to the eyes, kidneys, spine, arms, legs or other organ. The most serious complication of A-fib is arterial thromboembolism, or the sudden blockage of blood flow to an organ by a blood clot. The most identifiable occurrence of this is ischemic stroke.

A stroke can occur when an artery in the brain is blocked by a clot (thrombus) or a piece of clot that traveled from elsewhere, such as the heart (embolus). This blockage can lead to permanent brain damage and can even be deadly. A-fib related strokes are nearly twice as fatal and twice as disabling as non-atrial fibrillation related strokes. A-fib is also associated with longer transient ischemic attacks (TIAs), also known as “mini-strokes”. All of the impact that A-fib has on stroke may be due to larger clots.

A patient’s risk of stroke increases with age. Without medication, each year about 1.3 percent of people with A-fib who are between the ages of 50 and 59 have a stroke. The risk gradually increases each year, with about 5 percent of A-fib patients 80 to 89 years old having a stroke. Other stroke risk factors include: