What is atrial fibrillation?

Atrial fibrillation is a heart rhythm disorder, where your heart beats too fast or too slow. It is the most common heart disorder in the world.

Unfortunately, if you have the condition, it can increase your risk of stroke by up to five times. However, your doctor can prescribe blood-thinning medications which can greatly reduce your risk.


What are the causes of atrial fibrillation?

The heart is made up of chambers surrounded by muscular walls. There are two chambers at the bottom of the heart, called ventricles, and two at the top, called atria.


When the heart beats normally, the muscular walls of the atria and ventricles tighten and squeeze (contract), in turn, to push blood out of the heart and around the body. The muscular walls then relax to allow blood to fill the heart.

When you have atrial fibrillation, the atria (upper chambers) contract randomly and sometimes faster than normal. This means that your heart muscles can’t relax properly and reduces how well the heart can work.

Atrial fibrillation happens due to abnormal electrical impulses in your heart – they start firing randomly in the atria which overrides your heart’s natural pacemaker. This causes an irregular heart rhythm and pulse rate.

It’s not fully understood how it is caused, but we do know that the chances of having it increase with age and affects those over 65 the most. However, it can affect adults of any age.

It is also more likely to occur if you have other conditions, such as high blood pressure, atherosclerosis – where your arteries become narrowed due to a build-up of fatty deposits, or heart valve problems.

For some, there is no clear reason why they get the condition.

What are the symptoms of atrial fibrillation?

You might not experience any symptoms if you have atrial fibrillation. This is one of the reasons why many have it and remain undiagnosed – an estimated 1-2% of the world’s population is living with undiagnosed atrial fibrillation.

If you do have symptoms, you may experience:

  • tiredness/fatigue
  • breathlessness
  • palpitations (where you suddenly notice your heart beating strongly)
  • a heart rate that’s consistently lower than 60 or above 100 beats per minute
  • reduced ability to exercise
  • chest discomfort
  • dizziness.

You should see your doctor if you experience any of the above symptoms.

We have some of the world’s leading specialists in treating atrial fibrillation. Get in touch with our customer services team to book an appointment.  

How do you diagnose atrial fibrillation?

Your doctor may perform a range of tests to help diagnose atrial fibrillation. These include:

Electrocardiogram (ECG or EKG)

An ECG detects whether your heart rhythm and its electrical activity (that stimulate heart beats) is normal. 

It takes about 5 minutes and is pain-free. Small stickers called electrodes are attached to your chest, arms and legs and are connected by wires to an ECG machine which records your heart’s electrical activity.


This is an ultrasound scan of your heart. An ultrasound is a procedure that uses high-frequency sound waves to develop a picture of your heart. It is used to check the structure of your heart and its valves, and whether it is functioning correctly.

Chest X-ray

Sometimes, lung problems may cause atrial fibrillation and an X-ray of your chest may be used to check if that is the case.

Blood tests

A range of blood tests can be used to determine underlying health conditions that may be causing the symptoms you are experiencing.   

How is atrial fibrillation treated?


Your doctor can prescribe blood-thinning medications called anticoagulants (an·tee·kow·a·gyoo·luhnt) to help reduce your risk of a stroke, which is common with atrial fibrillation.

They may also prescribe medications that can help control your heart rate and return it to normal. These include beta blockers and calcium channel blockers.


Cardioversion may be recommended and is a procedure that involves giving your heart a controlled electric shock to help return its rhythm to normal.

It is usually carried out in hospital so that your healthcare team can keep a close eye on your heart until they feel it is safe for you to return home.

Catheter ablation

Catheter ablation is a procedure that involves very carefully destroying the diseased area of your heart that is responsible for the irregular electrical activity. It is an option if medication has not worked for you or you can’t tolerate it.

During the procedure, a catheter – a soft, thin wire – is guided through one of your veins up to your heart where it is used to record its electrical activity locally. Once the source of the abnormal electrical activity in your heart is identified, a high-frequency radio wave is used to heat the diseased part of your heart to destroy the tissue.

Catheter ablation normally takes two to three hours to complete and so you may be put to sleep with general anaesthetic during the procedure. You should recover quickly and be able to carry out most of your normal activities the next day.


Pacemakers are usually used to stop your heart beating too slowly but may be used for atrial fibrillation to help it beat regularly.

A pacemaker is a small battery-operated device and it is implanted surgically in your chest, just below your collarbone. It’s a minor surgical procedure that can be carried out with local anaesthetic (numbing the area to be operated on) whilst you are awake.

Pacemakers may be used if your heart is not responding to medication or they are unsuitable for you to take. This is most often in people aged over 80.