Download Atrial fibrillation is a heart condition that causes an irregular and

Atrial fibrillation is a heart condition that causes an irregular and often
abnormally fast heart rate.
CSF026 ATRIAL FIBRILLATION
A normal heart rate should be between 60 and 100 beats a minute when you're resting, and is
regular. You can measure your heart rate by feeling the pulse in your wrist or neck. In atrial
fibrillation, the heart rate may be over 140 beats a minute, although it can be any speed.
The main difference between a normal rhythm and atrial fibrillation is that you are unable to
predict when the next heart beat will come along, as heart rate is irregular.
This may lead to a number of problems, including dizziness and shortness of breath. You
may also be aware of a fast and irregular heartbeat (palpitations) and feel very tired.
Read more about the symptoms of atrial fibrillation.
Some people with atrial fibrillation have no symptoms and are completely unaware that their
heart rate is not regular.
When to see your GP
Make an appointment to see your GP if:
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you notice a sudden change in your heartbeat
your heart rate is consistently lower than 60 or above 100 - especially if you are
experiencing other symptoms of atrial fibrillation
See your GP as soon as possible if you have chest pain.
What happens in atrial fibrillation?
When the heart beats normally, its muscular walls contract (tighten and squeeze) to force
blood out and around the body. They then relax, so the heart can fill with blood again. This
process is repeated every time the heart beats.
In atrial fibrillation, the upper chambers of the heart, called the atria, contract randomly and
sometimes so fast that the heart muscle cannot relax properly between contractions. This
reduces the heart's efficiency and performance.
Why it happens
Atrial fibrillation occurs when abnormal electrical impulses suddenly start firing in the atria.
These impulses override the heart's natural pacemaker, which can no longer control the
rhythm of the heart. This causes you to have a highly irregular pulse rate.
The cause is not fully understood, but it tends to occur in certain groups of people (see below)
and may be triggered by certain situations, such as drinking excessive amounts of alcohol or
smoking.
Read more about the causes of atrial fibrillation.
Atrial fibrillation may be defined in various ways, depending on the degree to which it affects
you:
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Paroxysmal atrial fibrillation - this comes and goes and usually stops within 48
hours without any treatment.
Persistent atrial fibrillation - this lasts for longer than seven days (or less when it is
treated).
Longstanding persistent atrial fibrillation - this means you have had continuous
atrial fibrillation for a year or longer.
Permanent atrial fibrillation - atrial fibrillation is present all the time and no more
attempts to restore normal heart rhythm will be made.
Who is affected?
Atrial fibrillation is the most common heart rhythm disturbance and affects up to 800,000
people in the UK.
Atrial fibrillation can affect adults of any age. However, it affects more men than women
and becomes more common the older you get. It affects about 10% of people over 75.
Atrial fibrillation is more likely to occur in people with other conditions, such as high blood
pressure or atherosclerosis.
It's uncommon in younger people, but may be slightly more common in people with another
heart condition, such as a heart valve problem.
Treating atrial fibrillation
Atrial fibrillation is generally not life threatening, but it can be uncomfortable and often
needs treatment.
Treatment may involve:
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medication to prevent a stroke
medication to control the heart rate or rhythm
cardioversion, where the heart is given a controlled electric shock to restore normal
rhythm
cather ablation, to prevent atrial fibrillation from occurring
having a pacemaker fitted to help your heart beat regularly