I am
Show me:
Show me:
What is an arrhythmia?
heartfoundation.org.au|Helpline 13 11 12

What is an arrhythmia?

Arrhythmia is a fault in the heart’s electrical system, which affects your heart’s pumping rhythm.

Key takeaways

  • Arrhythmia is a fault in the heart’s electrical system, which affects your heart’s pumping rhythm. 
  • Heart arrhythmias are a range of conditions, which have a range of outcomes.  
  • Common symptoms include: shortness of breath, weakness, dizziness, light-headedness, fainting or feeling fainting, a racing heart or palpitations and chest pain or discomfort. 
  • Most arrhythmias are not life-threatening, but can still cause complications that are best managed with your healthcare team. 
3 min read
The heart has its own electrical system. Electrical impulses are essential to make your heart beat to pump blood to your entire body. Your heart has four chambers, two on the right and two on the left. It has two upper chambers (atria) and two lower chambers (ventricles). In a healthy heart, regular electrical signals cause these four chambers to contract and relax in a steady rhythm of 60 to 100 beats per minute. 

What is arrhythmia? 

Arrhythmia is a fault in the heart’s electrical system, which affects your heart’s pumping rhythm. The abnormal electrical activity makes the heart muscle beat too fast, slow or in an irregular way.  

In a healthy heart, you don’t feel your heartbeat. That’s why if you feel your heart beating too fast, too slowly or irregularly, you should see your doctor. Most arrhythmias are not life-threatening, but can still cause complications that are best managed with your healthcare team. 

Types of arrhythmias 

Arrhythmias are a range of abnormalities in the heart’s electrical system that controls its pumping rhythm. They’re classified by whether they start in the atria or ventricles. They’re also classified by the speed of heart rate they cause: fast heartbeat (tachycardia), slow heartbeat (bradycardia) or irregular heartbeat. There are many types of heart arrhythmia. 

Atrial fibrillation 

Abnormal electrical activity in the heart’s top chambers overwhelms the heart’s electrical system. This causes the heart’s electrical messages to become chaotic. As a result, the heart’s top two chambers (atria) twitch rather than contract. The atria beat rapidly and out of rhythm with the heart’s lower two chambers (ventricles). Read more about atrial fibrillation, the most common arrhythmia. 

Atrial flutter  

Atrial flutter is similar to atrial fibrillation. However, in this condition the heart rhythm is more regular and less chaotic than the abnormal rhythm in atrial fibrillation. Sometimes an atrial flutter can develop into atrial fibrillation and vice versa.  

Ectopic heartbeats  

This arrhythmia occurs when your heart misses a beat or adds an extra beat. Ectopic beats can occur in the top (atria) or bottom (ventricle) heart chambers. This can occur in healthy individuals. 

Paroxysmal arrhythmias  

This is when the arrhythmia starts and stops suddenly. Episodes of paroxysmal arrhythmia can last for seconds, minutes, hours or up to a week. Paroxysmal arrhythmias may have certain triggers. 

Heart block (atrioventricular heart block and bundle branch block) 

Heart block – also known as atrioventricular (AV) heart block and bundle branch block – is a delay or a blockage of the heart’s electrical messages. This may cause your heart to pump abnormally or your heart rate to slow to less than 60 beats per minute. 

Long QT syndrome, Brugada syndrome and Wolff-Parkinson-White (WPW) syndrome 

Each of these can cause fast and irregular heartbeats. These conditions are related to a specific abnormality in the heart electrical system that can lead to fainting spells or even cardiac arrest.    

Supraventricular tachycardia (SVT) 

These are a group of arrhythmias caused by abnormal electrical activity in the heart’s atria. This causes the heart rate to increase very suddenly to over 100 beats per minute.  

Tachybrady syndrome (sick sinus syndrome)  

This arrhythmia occurs because of a problem with your heart’s natural pacemaker (sinus node), a part of its electrical system. This causes the heart rate to vary from very fast to very slow. 

Ventricular tachycardia 

This arrhythmia is caused by abnormal electrical activity in the heart’s ventricles. This causes a fast heartbeat that can start very quickly and last for seconds, or go on for longer. If it continues, it must be treated as soon as possible due to the risk of cardiac arrest. 

Ventricular fibrillation  

Ventricular fibrillation is caused by abnormal electrical activity in the heart’s ventricles that causes a very fast, erratic and ineffective pumping rhythm. When the heart does not pump effectively, cardiac arrest occurs and urgent treatment is required to restart the heart rhythm and save the person’s life.  

Are arrhythmias serious? 

Arrhythmias are a range of conditions, which have a range of outcomes. Some arrhythmias can be well managed by your doctor as a long-term condition. Other arrhythmias are life-threatening and require urgent treatment. Sometimes, an arrhythmia is a symptom of an underlying condition that requires management by your doctor.  

Arrhythmia symptoms 

An irregular heartbeat can be a sign of arrhythmia, or another heart condition. That’s why if you feel your heart beating too fast, too slowly or irregularly, you should see your GP.  

Occasionally, people with a healthy heart may have an irregular heart rhythm or palpitation during a time of emotional or physical stress. This is normal. Noticeable palpitations don't necessarily mean you have a serious problem.  

Arrhythmia symptoms include: 
  • Anxiety 
  • Chest pain 
  • Fainting (syncope) 
  • Fatigue 
  • Fluttering or pounding in your chest 
  • Light-headedness or dizziness 
  • Racing heartbeat when feeling at the wrist (tachycardia) 
  • Slow heartbeat when feeling at the wrist (bradycardia)  
  • Shortness of breath 
  • Sweating
Some arrhythmias don’t cause any symptoms. Your GP might find you have an arrhythmia before you do, during a check-up.  

Causes of arrhythmia  

There are some conditions that can lead to an arrhythmia, including: 
  • A heart attack 
  • Congenital heart disease  
  • Coronary heart disease  
  • Diabetes 
  • High blood pressure 
  • Heart failure 
  • Obstructive sleep apnea (OSA) 
  • Structural heart abnormalities – such as from cardiomyopathy, valve disease or scarring from a previous heart attack. 
  • Thyroid problems
 Risk factors for arrhythmia are: 
  • Aging 
  • Being overweight 
  • Drinking too much alcohol or caffeine 
  • Drug abuse 
  • Electrolyte imbalance 
  • Genetics 
  • Smoking 
  • Some medications and supplements, including over-the-counter cold and allergy medications and weight loss or nutritional supplements 
  • Stress or anxiety. 

Arrhythmia triggers 

If you have an irregular heartbeat that comes and goes (paroxysmal arrhythmia), there are certain triggers that may include:  
  • Alcohol 
  • Caffeine 
  • Nicotine (either cigarettes or e-cigarettes) 
  • Tiredness 
  • Unrelated illness such as a cold or flu 
  • Some medications (either over-the-counter or prescription).  
  • Stress (physical or emotional). 
It’s a good idea to work out what triggers your arrhythmia and avoid those triggers where possible.  

Talk to your doctor if you think your medication may trigger your arrhythmia. Never stop taking prescription medication without talking to your doctor first. 

In some people, certain types of exercise may trigger your arrhythmia. If you think this is happening to you, talk to your doctor. Physical activity is very important for your heart health and overall wellbeing and should not be avoided without talking to your doctor first. 

Your doctor can help you manage your health and suggest alternative medication or activities that are suitable for you. 

Diagnosing arrhythmia 

To diagnose an arrhythmia, your doctor will review your signs and symptoms and conduct a physical examination.  

They may perform the following diagnostic tests to confirm arrhythmia or rule out other conditions: 
  • Electrocardiogram (ECG) – This test measures your heart’s electrical signals and  the timing and duration of each electrical phase in your heartbeat. 
  • Holter monitor – This is a portable ECG. It records your heart's activity for 24 hours or longer. 
  • Event recorder – This is also a portable ECG. It records your heart's activity over weeks to months. 
  • Echocardiogram – This test creates moving pictures of your heart. It may diagnose structural heart disease or blood clots in your heart. 
  • Implantable loop recorder – This may be implanted under your skin in the chest area to continually record your heart's electrical activity and detect abnormal heart rhythms. 
  • Stress test (exercise testing) – This test measures arrhythmias triggered by exercise. 
  • Tilt table test – This test monitors your heart rate and blood pressure as you lie flat on a table and how your heart responds when you stand up. 
  • Electrophysiological testing and mapping – In this test, electrodes can map the spread of electrical impulses through your heart. Doctors can use the electrodes to stimulate the heart to trigger an arrhythmia. 

Arrhythmia treatment

Arrhythmia treatment may only be required if the arrhythmia is life-threatening, or causes significant symptoms or serious health problems. Treatment depends on the cause of the arrhythmia and how it impacts your health. 

These include:  
  • Electrical cardioversion – An electrical shock to the chest done under general anaesthesia to restore the heart’s normal electrical rhythm. 
  • Catheter ablation – A procedure performed in hospital using a catheter to destroy (ablate) the area inside the heart that is causing the abnormal rhythm. If your doctor recommends an ablation, they will discuss the benefits and risks with you. 
  • Medication – Regular medication can be given to normalise the heart’s rhythm (anti-arrhythmic agents) or slow the heart rate (beta-blockers, some calcium channel blockers and digoxin). Blood thinning (anticoagulation) medications may be prescribed if your doctor feels your arrhythmia increases your risk of stroke.   
  • Pacemaker – A small implantable device that electrically stimulates the heart to maintain a regular heart rhythm. 
  • Implantable cardiac defibrillator (ICD) – To continuously monitor and correct your abnormal heart rhythms as needed. 
  • Automate External Defibrillation (AED) – A mild electrical current is used to ‘reset’ your heart rhythm in a cardiac arrest.  

Living with an arrhythmia 

If you’ve been diagnosed with an arrhythmia, you may have a lot of questions. You may wonder how serious your condition is and what it means for the future. 

It's normal to feel many emotions such as fear, anxiety and low mood. Talk to your doctor if these feelings last longer than two weeks. There are steps you can take to help you manage your condition and relieve any worries you may have.  

To help manage your condition, you can: 
  • Ask your doctor questions to understand your arrhythmia and its treatment 
  • Identify your arrhythmia triggers 
  • Avoid or reduce alcohol intake 
  • Always take your medication as prescribed 
  • Know when to seek urgent help 
  • Stay physically active 
  • Manage your risk factors for heart attack, as they are also important in management of arrhythmias 
  • Attend cardiac rehabilitation – structured exercise and education about heart health. 

Remember that the Heart Foundation Helpline is available to give you further information and support you. Call 13 11 12 Monday to Friday during business hours. 

You might also be interested in

Cardiac arrest at 33: the challenges of restarting your life

Cardiac arrest at 33: the challenges of restarting your life

Cardiac arrest at 33: the challenges of restarting your life

Emma shares her story and opens up about her emotional struggles....

What is angina?

What is angina?

What is angina?

Angina is a type of chest pain or discomfort that’s a symptom of an underlying heart problem, usually coronary heart disease (CHD)....

Blood pressure and your heart

Blood pressure and your heart

Blood pressure and your heart

Understand blood pressure and how it can impact your heart health....

Lessons learned: recovering from open heart surgery

Lessons learned: recovering from open heart surgery

Lessons learned: recovering from open heart surgery

After having five open heart surgeries between the ages of 13 and 41, Peter knows a thing or two about recovery....

What is atrial fibrillation?

What is atrial fibrillation?

What is atrial fibrillation?

Atrial fibrillation is a type of arrhythmia where your heart beats irregularly and fast....

Blood cholesterol

Blood cholesterol

Blood cholesterol

Keeping your blood cholesterol at a healthy level can help you reduce your risk of heart disease and other serious conditions. ...

Fit, active and healthy – Sharon wasn’t expecting a heart attack

Fit, active and healthy – Sharon wasn’t expecting a heart attack

Fit, active and healthy – Sharon wasn’t expecting a heart attack

Fit, active and healthy, Sharon wasn’t expecting a heart attack. However, after experiencing a ‘widow maker’, she counts herself lucky....

What is a cardiac arrest?

What is a cardiac arrest?

What is a cardiac arrest?

With immediate help a cardiac arrest can be survived. Learn how to save a life....

Heart health information in your language

Heart health information in your language

A selection of heart health information brochures in a range languages...

What is coronary heart disease?

What is coronary heart disease?

What is coronary heart disease?

Coronary heart disease (CHD) or coronary artery disease occurs when a coronary artery clogs and narrows because of a buildup of plaque....

What is a heart attack?

What is a heart attack?

What is a heart attack?

The most common cause of a heart attack is coronary heart disease....

Heart conditions in women

Heart conditions in women

Heart conditions in women

Like men, women can be diagnosed with a range of heart conditions....

Heart disease and pregnancy

Heart disease and pregnancy

Heart disease and pregnancy

Pregnancy is often referred to as the “ultimate stress test” for the body....

What is heart failure?

What is heart failure?

What is heart failure?

Heart failure is a condition where your heart isn’t pumping as well as it should be....

What is heart valve disease?

What is heart valve disease?

What is heart valve disease?

Heart valve disease means that your heart valve or valves don't open or close properly....

What is heart disease?

What is heart disease?

What is heart disease?

Heart disease is the broad term for conditions that affect the structure and function of the heart muscle. ...

MyMarathon

MyMarathon

MyMarathon

The fundraising race where you set the pace. Run, jog or walk MyMarathon at your own pace during October....

Clinical Guidelines

Clinical Guidelines

Clinical Guidelines

Full list of clinical guidlines and references for CVD, heart failure, ACS, hypertension, atrial fibrillation, SCAD and RHD...

Help make heart disease history!

Help make heart disease history!

Help make heart disease history!

48 Australians die from heart disease every day. You can help save lives....

Are you at risk of heart disease?

Are you at risk of heart disease?

Are you at risk of heart disease?

There is no single cause for any one heart condition, but there are risk factors that increase your chance of developing one. ...

Support us and help save Australian hearts

Support us and help save Australian hearts

Support us and help save Australian hearts

Join the fight against Australia’s biggest killer by supporting the Heart Foundation.  ...

Fundraise to save Australian hearts

Fundraise to save Australian hearts

Fundraise to save Australian hearts

Join the Heart Foundation community. Together, we can make a real difference for Australian hearts. ...

Support and resources for health care professionals

Support and resources for health care professionals

Support and resources for health care professionals

Our range of clinical and patient support resources are available for you to use in your daily practice....

Vegetarian recipes

Vegetarian recipes

Vegetarian recipes

Search through our vegetarian recipes...

Meditation helped Grant recover from his heart attack

Meditation helped Grant recover from his heart attack

Meditation helped Grant recover from his heart attack

Thankfully for Grant Byrne, a lifelong Led Zeppelin fan, some quick thinking helped him avoid a stairway to heaven. Read Grant’s heart attack story now. ...

WEBINAR | Absolute CVD risk assessment practical update

WEBINAR | Absolute CVD risk assessment practical update

A multidisciplinary panel of experts discuss the practical application of absolute CVD risk assessment through Heart Health Checks....

Your heart is your most important tool

Your heart is your most important tool

Your heart is your most important tool

Men’s Health Week is the perfect time to think about your heart....

Key Statistics: Cardiovascular Disease

Key Statistics: Cardiovascular Disease

Key data and statistics about CVD....

Supporting SA cardiac patients and health professionals with free resources

Supporting SA cardiac patients and health professionals with free resources

Supporting SA cardiac patients and health professionals with free resources

We want to make it easier for South Australians to lead heart-healthy lives....

Aboriginal and Torres Strait Islander Training Centre

Aboriginal and Torres Strait Islander Training Centre

Training to support identification of Aboriginal and Torres Strait Islander patients, in line with standard practice....

Cardiac arrest at 26: adjusting to a new ‘normal’

Cardiac arrest at 26: adjusting to a new ‘normal’

Cardiac arrest at 26: adjusting to a new ‘normal’

Hypertension clinical information and guidelines

Hypertension clinical information and guidelines

Clinical information for diagnosis and management of hypertension....

Absolute CVD risk calculator

Absolute CVD risk calculator

The Absolute CVD risk calculator estimates the likelihood of having a heart attack or stroke in the next five years....

Improving food supply

Improving food supply

Improving food supply

The Heart Foundation supports initiatives that guide people to healthier food and drink choices. ...

Sodium and salt converter

Sodium and salt converter

Convert the sodium listed on food products into grams of salt or vice versa. ...

Staying active for better heart health

Staying active for better heart health

Staying active for better heart health

Moving more every day is one of the best habits you can have....

Active Living NSW

Active Living NSW

Active Living NSW

Active Living NSW supports physical activity and healthy built environments in NSW ...

Building physical activity into urban planning and design

Building physical activity into urban planning and design

Building physical activity into urban planning and design

Resources available for built environment professionals to help guide in the development of active outdoor and indoor spaces....

What is coronary heart disease?

What is coronary heart disease?

What is coronary heart disease?

Coronary heart disease (CHD) or coronary artery disease occurs when a coronary artery clogs and narrows because of a buildup of plaque....

What waist measurements mean for your heart

What waist measurements mean for your heart

What waist measurements mean for your heart

How your waist measurement contributes to your heart health...

Clinical resources: Coronary heart disease and mental health

Clinical resources: Coronary heart disease and mental health

The prevalence of depression is high in patients with coronary heart disease (CHD)....

Supporting Your Emotional Wellbeing: An Online Forum for Young Heart Patients

Supporting Your Emotional Wellbeing: An Online Forum for Young Heart Patients

Supporting Your Emotional Wellbeing: An Online Forum for Young Heart Patients

Risk factors for women

Risk factors for women

Risk factors for women

In Australia, 90% of women have one risk factor for heart disease, and 50% have two or more. ...

Support after a heart attack

Support after a heart attack

Support after a heart attack

Many different thoughts may go through your head after a heart attack and you may be presented with complicated medical info. Know where to get support. ...

Pregnancy and heart disease

Pregnancy and heart disease

Information and resources for health professionals....

Healthy Food Access Tasmania

Healthy Food Access Tasmania

Healthy Food Access Tasmania

We've been working on several projects with local governments across Tasmania, big and small....