How is atrial fibrillation related to stroke?

A stroke occurs when the blood supply to any part of the brain is cut off due to either a clot or a bleed. Blood that travels from the heart to the brain contains oxygen, and without this oxygen the cells of the brain cannot survive and will die. Every year, 15 million people worldwide experience a stroke. Of these, 5.7 million are lethal, and another 5 million cause permanent disability. People with AF are 5 times more likely to experience a stroke, and these strokes tend to be more severe than those caused by other conditions. One hypothesis for this is that clots formed in the heart tend to be much larger than the ones caused by other conditions. This means that the clots get lodged in larger blood vessels in the brain, causing a larger amount of the brain to be affected by the stroke. 16, 23, 25

▶  What is stroke

What are the symptoms of stroke?

To remember the signs of a stroke and what to do, think FAST. 17 If you suspect that you or someone else is having a stroke, you need to act 'FAST':

  • Facial weakness – Can you smile? Has your mouth or eye drooped?
  • Arm weakness – Can you raise both arms?
  • Speech problems – Can you speak clearly and can you understand what others are saying?
  • Time to call emergency services.
▶  More About Signs and symptoms

The risk of stroke is increased almost 500% in people with atrial fibrillation. 16

"Many AF-related strokes could be prevented"

Chris Macey
Irish Heart Foundation

Who is likely to have a stroke?

While predominantly affecting the elderly, approximately 25% of strokes occur in people aged below 65 years. 18

Several risk factors other than age contribute significantly to stroke risk. Principal among them are atrial fibrillation, heart failure, heart disease, and high blood pressure.

▶  Understand Your Stroke

One in six people worldwide will have a stroke in their lifetime. 19