Complications of AF

Even though atrial fibrillation (AF) itself is generally not life-threatening, it increases your risk of having a stroke. The risk ranges from less than 1% per year to about 20% per year, depending on age and other medical conditions. 

Understanding your AF and managing your AF will help you reduce your risk of stroke.


Roughly 1 in 3 strokes occur as a result of AF. A stroke caused by AF is from a sudden blockage of the flow of blood to part of the brain, causing it to stop working and eventually damaging brain cells. A stroke is also known as a cerebrovascular accident (CVA). 

AF is an important risk factor for stroke. However strokes also occur without AF and the risk factors that lead to the majority of strokes are very similar to heart attacks. Any intervention be it lifestyle changes or medication, for example to lower blood pressure or cholesterol, lower not only the chance of having a heart attack but the risk of having a stroke.

Atrial Fibrillation and Stroke Risk

Your doctor will discuss your risk of stroke and the available treatment options if your risk is increased.

People with AF have, on average, a 7% risk of experiencing a stroke each year.  This risk adds up over time. Individual risk varies a bit and can be more accurately estimated using a risk assessment tool.

You can estimate your level of risk together with your health professional using the CHADS2 VASc score. This is likely to involve answering questions about other risk factors such as your age, personal history of heart disease or stroke, and any other medical conditions you have.

The level of risk will determine what treatments are recommended and your doctor will discuss these treatments, including the benefits and risks, with you. Find more information on lowering your risk of stroke.

Reasons why AF increases risk of stroke

When you have an arrhythmia (irregular heartbeat) like AF, blood doesn’t flow as well through the heart and can collect in the atria. As a result this collected or pooled blood is more likely to clot (thicken into lumps). These clots could break off and travel to the small vessels in the brain.

Atrial fibrillation clot stroke

What is worrying is that a clot could block one of the blood vessels, cutting off vital blood supply and damaging part of the brain.

This is called an Embolic Stroke. The damage caused will affect how your body functions.

You have an important role to play in your health. There are things you can do today to lower your risk of stroke.

Stroke Signs and Symptoms

A stroke can happen suddenly, occur without any warning and have immediate and long term effects. Stroke symptoms generally depend on what part of the brain is affected. It may be the part that enables you to talk or walk or the part that controls your left arm.

It is important to be aware of the common warning signs of a stroke and to act fast. You should call 111 if you suspect a stroke.Fast Stroke action planUsing the acronym F.A.S.T, here are some symptoms that you need to look out for that can help you to recognise a possible stroke. Share these with your family and friends so they know what to look out for also:

FACE - has their face drooped on once side?

ARM - Can they raise both their arms?

SPEECH - Is their speech slurred or jumbled? Do they understand what you are saying?

TIME - Time is critical and minutes matter. If you observe any of these signs, call 111 immediately. 

The signs may last for a few minutes to hours and may disappear or they may be ongoing.

Don't wait to see what happens. Act FAST and call 111 immediately.

For more information on stroke visit the Stroke Foundation.