The fast, irregular rhythm that occurs with atrial fibrillation prevents the heart muscles from contracting properly. This means the heart cannot pump blood as effectively as it should. Since blood is not properly pumped away from the heart, it may collect or ‘pool’ in the heart chambers, leading to the formation of a clot. The clot can break off from the heart wall and travel to the blood vessels of the brain, where it can lodge and block blood flow to that region of the brain, causing a stroke.
People with AF are five times more likely to have a stroke compared to those who do not have AF. Clots may also lodge in arteries supplying blood to your arms and legs, or one of your vital organs, such as the bowel or kidney.
Some people with AF are at relatively low risk of stroke (e.g. 1% or even less per year). However, some people with AF are at very high risk of stroke – as high as 20% each year.
Doctors have tools to work out an individual’s risk, and thereby decide the best treatment option.
What are the symptoms of stroke?
It is important to be aware of stroke symptoms, particularly if you have AF. There are some simple things you can look out for that can help you recognise a stroke – facial weakness, arm weakness and difficulty with speech are the most common signs. Strokes can happen suddenly and have immediate and lasting effects. The National Stroke Foundation recommends using the FAST test when you suspect someone is having a stroke.
FAST will help you and your family recognise the symptoms of a stroke quickly so you can get medical assistance as soon as possible. The faster you seek medical assistance, the better your prospects of recovering from the effects of a stroke.