Atrial fibrillation

Medically written by
Dr David Chandrakumar
BMed, MD, FRACP
Cardiologist
Consultant Cardiologist
Last reviewed: July 2026

What is atrial fibrillation?

Atrial fibrillation is a condition where the heart beats in an irregular rhythm. It starts in the upper chambers of the heart, called the atria, when the electrical signals that control the heartbeat become disorganised. This can lead to an irregular and sometimes rapid heartbeat. Some people have short episodes that come and go. Others have atrial fibrillation that lasts longer or is permanent.

Atrial fibrillation isn’t always immediately dangerous, but it does need proper medical attention. When the heart isn’t beating in a steady pattern, blood can pool inside the heart and form clots. If a clot travels to the brain, it can cause a stroke. It also reduces the efficiency of the heart’s pumping function, leading to dizziness or shortness of breath. Treatment can help lower the risk of stroke and improve symptoms.

Atrial fibrillation symptoms

Atrial fibrillation can feel different from person to person. You may notice your heart suddenly racing, skipping beats or fluttering in your chest. Some people describe it as feeling as though their heart is ‘out of rhythm’.

Symptoms may include:

• Heart palpitations
• An irregular pulse
• Shortness of breath
• Tiredness or reduced stamina
• Dizziness or feeling faint
• Chest discomfort
• Feeling unusually weak during activity

Some people don’t feel anything unusual. Atrial fibrillation may only be picked up during a pulse check, heart tracing (ECG) or investigation for another health concern.

You should seek urgent medical help if you have chest pain, fainting, severe breathlessness or signs of a stroke, such as facial drooping,  weakness of parts of your body or difficulty speaking.

What causes atrial fibrillation?

Atrial fibrillation becomes more common with age, but it can also be linked to conditions that place extra strain on the heart. Possible causes and risk factors include:

• High blood pressure
• Coronary artery disease
• Heart valve disease
• Heart failure
• Diabetes
• Sleep apnoea
• An overactive thyroid
• Obesity
• High alcohol intake
• Previous heart surgery

It can also appear during periods of physical stress, such as a severe infection or another acute illness. In some people, there isn’t one clear cause, which is why a detailed review is helpful.

Diagnosing atrial fibrillation

Your doctor will start by asking what you’ve noticed, how often symptoms happen and how long they last. They’ll also check your pulse, blood pressure and general cardiovascular risk.

The key test for atrial fibrillation is an electrocardiogram, also called an ECG. This is a simple test that records the electrical activity of your heart. If your symptoms come and go, a standard ECG may not capture an episode. In this case, your doctor may suggest a portable heart monitor (Holter monitor or Heart Bug) that records your rhythm over a longer period.

You may also need blood tests to check for contributing factors, such as thyroid problems. An echocardiogram, an ultrasound scan of the heart, is also helpful to understand if there is an underlying cause for the atrial fibrillation, such as a valve defect, and the effect of this rhythm on the heart’s function.

Atrial fibrillation treatment

Treatment for atrial fibrillation is personalised. Your specialist will consider your symptoms, medical history, stroke risk and the pattern of your heart rhythm before recommending a plan.

Treatment may include:

• Medication to reduce the risk of stroke
• Medicine to slow the heart rate or restore a normal rhythm
• Procedures to help restore a steadier rhythm
• Support for related conditions, such as high blood pressure or sleep apnoea
• Lifestyle advice to support heart health

Some people may be offered a cardioversion. This aims to return the heart to a steadier rhythm. It can be done using a controlled electrical treatment or medication, depending on your situation.

Catheter ablation may be suitable for some people. This is a specialist procedure that targets the area of the heart that triggers atrial fibrillation, aiming to completely cure the condition. 

The right approach depends on your individual risk and how it’s affecting your daily life.

Access expert care with Complete Health Australia

If you’ve noticed palpitations, breathlessness, dizziness or an irregular heartbeat, it’s worth getting checked. If your Smart Watch has been alerting you to an irregular heart rhythm, it is worthwhile having tests to check if this is due to atrial fibrillation. Atrial fibrillation can often be managed effectively once it’s properly diagnosed.

Complete Health Australia can support you with specialist cardiology care, clear guidance and a treatment plan built around your needs.