Atrial Fibrillation

What is atrial fibrillation?

Atrial fibrillation (AF or AFib) is a disorder of the heart’s electrical activity, where your heart beats irregularly and often fast, and can lead to stroke, heart failure and even early death.

Why should we be concerned about atrial fibrillation?

Atrial fibrillation reduces your heart’s ability to pump blood and this lack of flow inside the atrium can lead to a blood clot. If this clot breaks away and travels to the brain, it can result in a stroke.

AF can trigger a rapid heart rate. This may reduce the filling of the ventricle and lead to heart failure. If high heart rates are sustained over time, this can weaken the heart muscle and lead to cardiomyopathy.

What are the symptoms of atrial fibrillation?

Atrial fibrillation symptoms can vary widely, with some patients experiencing no symptoms and others having severe symptoms. Some of the common ones to look out for include:

• Heart palpitations, sensation of fluttering or unevenness in the chest
• Chest discomfort, chest tightness
• Trouble breathing
• Dizziness
• Fatigue, lack of energy, difficulty exercising

There can be a disconnect between symptoms and risk so even when you have no symptoms, you can still be at risk of stroke or developing heart failure. Alternatively, having severe AF symptoms doesn’t necessarily mean you are more at risk of AF than someone with mild or no symptoms.

What are the risk factors for atrial fibrillation?

Some atrial fibrillation risk factors include:

• High cholesterol
• High blood pressure
• Obesity, a body mass index greater than 27 has been associated with increased risk of AF
• Inactivity
• Sleep apnoea
• Diabetes
• Excessive alcohol consumption
• Smoking
• Lack of sleep and fatigue

The risk factors mentioned above are ones which we can monitor and minimise. Some risk factors which cannot be controlled include:

• Age: Being over 60 increases your risk of developing AF;
• Family history: If you have a close family member with AF, your chance of getting AF goes up;
• Other medical conditions can also increase your risk of AF such as heart disease, thyroid problems, chronic kidney disease and lung disease. Some surgeries can also cause AF.

Genetics and Atrial Fibrillation

Scientists at the Institute are looking into what role genetics plays in the risk and treatment of AF. Professor Diane Fatkin is leading the research, and recently received a one million dollar grant to advance the groundbreaking work being done. Watch the video below as she explains how the funding is being used.

How is atrial fibrillation diagnosed?

Electrocardiogram (ECG) shows the electrical activity of your heart and is the main tool for diagnosing atrial fibrillation (AF).

Other tests that are often used to assess heart function and to look for causes of AF include:

• Echocardiogram shows a moving picture of your heart, to look at heart chamber size and contraction and to rule out blood clots
• Blood test
• Chest X-ray
• Implantable loop recorder can be placed under the skin to monitor the heart at all times, with a battery life of 3-4 years.
• Portable ECGs can record your heart’s activity over weeks or months
• Stress tests are exercise testing performed by your doctor

Over the last few years, there’s been a huge increase in technology available for use in the home. A monitor on your wrist, for instance, can give you an alert if you have an irregular heart rhythm or can take an ECG that can be sent straight to your doctor.

What treatments are available for atrial fibrillation?

• Pharmacological therapy: Medications can be used to try to restore the heart's rhythm to normal or to stop the heart from beating too fast
• Electrical cardioversion: An electric shock to the chest to restore the heart’s rhythm to normal
• Blood clot prevention: Medication can be used to thin the blood to prevent blood clots from forming
• Pacemaker: A small insertable device that regularly stimulates the heart through a small electrical pulse
• Medical procedures such as catheter ablation

How to reduce risk of developing atrial fibrillation?

Lifestyle changes that can be made to reduce the risk of developing atrial fibrillation include:

• Regular exercise, starting with daily walking
• Maintain a healthy weight with a BMI under 27
• Consume a healthy balanced diet
• Avoid smoking
• Reduce your stress
• Limit your alcohol intake to three standard drinks a week
• Manage other health conditions, such as high blood pressure, diabetes, sleep apnoea, thyroid problems, chronic kidney disease and lung disease

With the correct treatment and management AF can be managed and the patient can continue to have a long and active life.

How common is atrial fibrillation?

Atrial fibrillation is the most common type of heart rhythm disorder:

• Around half a million Australians are living with AF
• One in three individuals are at risk of developing AF in their lifetime
• AF affects 2% of the general population and one in 20 of those aged over 55
• The risk of developing AF increases with age
• AF is a major cause of stroke