This factsheet is for people who have atrial fibrillation or who would like more information about it.
Atrial fibrillation is when the heart beats too fast in an irregular rhythm. It is caused by faulty electrical signals in your heart and is the most common type of arrhythmia (irregular heartbeat).
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Published by Bupa's Health Information Team, June 2010.
Your heart is a muscular pump, responsible for delivering blood to the rest of your body. When your heart doesn’t beat in a normal way, it can’t do this as efficiently.
Atrial fibrillation mostly occurs in older people, affecting about seven in 100 people over the age of 65, although it can happen in younger people as well.
Your heartbeat is controlled by electrical signals (impulses), which travel through the heart making it contract. The signals travel from the atria (the upper chambers of the heart) to the ventricles (the lower chambers) through an area called the atrioventricular (AV) node. The AV node helps to synchronise the pumping action of the atria and ventricles.
Atrial fibrillation occurs when the electrical signals in the atria become disorganised, overriding the heart’s normal rate and rhythm. This causes the atria to contract irregularly or ‘fibrillate’.
There are three main types of atrial fibrillation:
Atrial fibrillation can cause a stroke and/or heart attack. This is because your blood isn’t flowing properly through your heart, so a blood clot can form. If a clot forms, it can block blood supply in your heart and cause a heart attack, or travel to your brain and cause a stroke. Because of this, people with atrial fibrillation are five times more likely to have a stroke than people without the condition.
If you have atrial fibrillation, you may need anticoagulant medicine (such as aspirin or warfarin) to prevent a clot forming.
Many conditions that affect the heart or blood circulation can cause atrial fibrillation, including:
Certain factors can also trigger temporary, reversible atrial fibrillation, including:
Many people develop atrial fibrillation without having any underlying cause or risk factor. This is called lone atrial fibrillation.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional.