What are arrhythmias?


Heart arrhythmias occur when the electrical impulses that regulate your heart are causing it to beat out of sync.

They can occur in a normal functioning heart and most commonly these are ectopic beats which people often feel as a missed beat or an occasional thump or flutter. But heart arrhythmia may be a sign that the electrical impulses that regulate your heartbeat aren’t working correctly.

When the electrical signals and the heart are healthy, most people have a resting heart rate of 60-100 beats a minute. However, when the electrical signals don’t fire properly, your heart can:

  • Beat too quickly (tachycardia) – resting heart rate faster than 100 beats a minute.
  • Beat too slowly (bradycardia) – resting heart rate less than 60 beats a minute (although this can be seen normally in young fit people).
  • Beat too early (premature contraction or ectopic beat) – extra beat in addition to normal heartbeat. This is often seen in normal hearts.
  • Beat erratically (fibrillation) – irregular heartbeat that may be very fast.

Are arrhythmias dangerous?

Are arrhythmias dangerous?

Palpitations are not always cause for concern. However, some can have serious health consequences because they may be a signal of significant heart arrhythmias. Therefore, palpitations need to be assessed and treated appropriately and should be discussed with your general practitioner or cardiologist if you have one.

What are the symptoms of an arrhythmia?

Older woman having a bad day

Heart arrhythmias may not always cause symptoms. Sometimes doctors detect an arrhythmia during a routine examination with no prior symptoms. However, common symptoms may include:

  • feeling your heart has skipped a beat
  • a racing heart
  • feeling your heart is beating slowly or pausing between beats
  • a fluttering feeling in your chest or neck
  • chest pain
  • shortness of breath

Less common symptoms of an arrhythmia include:

  • fatigue and or anxiety
  • dizziness
  • fainting or feeling faint
  • difficulty breathing
  • cough
  • weakness
  • unexplained sweating.

These symptoms are not exhaustive and may be caused by an arrhythmia or something else. Don’t ignore them. Speak to your GP or call 000 (triple zero) if you’re concerned.

What causes a heart arrhythmia?

What causes a heart arrhythmia?

Some arrhythmias have unknown causes, some are genetic, and others may have physical, medical, or emotional causes. Some of these include:


Some medications can trigger a heart arrhythmia.

High blood pressure

This can cause the heart walls to become stiff, changing how electrical signals travel through the heart. This is one of the most common causes of atrial fibrillation, a heart arrhythmia that may have serious consequences and needs to be recognised. Learn more. 

Previous heart attack or heart surgery

Any damage or scarring to the heart increases the risk of an arrhythmia.


People with diabetes can be at increased risk of a heart arrhythmia.

Overactive thyroid

Thyroid disorder can increase your risk of an irregular heartbeat.

Imbalance of electrolytes in your body

These electrolytes, especially  low magnesium & potassium, are important in the control of electrical impulses in the heart.

Sleep apnoea

This causes you to pause breathing while you sleep and can lead to a slow or irregular heartbeat.

Lifestyle factors

  • stress or anxiety
  • caffeine, nicotine or illegal drugs
  • excessive alcohol
  • exercise

How is an arrhythmia diagnosed?

Meeting with a Patient

Usually, your GP will ask questions about your family history and lifestyle, as well as about any symptoms you might be having. They’ll also do a physical examination. They might ask you to have a test to help with diagnosis. The first step in investigating arrhythmias is to try and get some form of ECG when a person is experiencing palpitations. Tests include:

Electrocardiogram (ECG or EKG)

This records your heart’s electrical signals with electrodes stuck to your chest, arms, and legs. Learn more.


Also known as an echo or a cardiac echo, this is a type of ultrasound that takes images of your heart. Learn more.

Ambulatory ECG Monitoring

One option is a Holter monitor, a small wearable ECG device that records your heart rate and rhythm over a 24 or 48-hour period. Another option is event monitoring. This is similar to Holter monitoring, but the device is worn for up to 7 days and records only when the patient activates it after feeling symptoms. Learn more.

Exercise Stress Test

This compares your heart’s performance before and after exercise. Learn more.

Implantable Loop Recorder

This small cardiac device is implanted just below the skin to record your heart rate and rhythm. It’s usually used when symptoms are infrequent.

Tilt Table Test

This may be used if you are prone to fainting. It measures how your heart and blood pressure respond as you stand up and lie down.

Electrophysiology Study (EPS)

Thin, flexible tubes with electrodes on the end are threaded through the blood vessels so they can map the spread of electrical impulses through your heart.

Home wearables

Now many fitness devices such as smart watches have ECG monitors built in and there are also commercially available products that can turn your smartphone into an ECG. These are often useful for intermittent and infrequent arrhythmias that would otherwise but hard to document.

How are heart arrhythmias treated?

Some arrhythmias need treatment by a cardiologist. However, many arrhythmias don’t need treatment but should still be assessed. If you don’t need specialist treatment, your doctor may encourage you to eat well, reduce your alcohol intake, stop smoking and manage your blood pressure and cholesterol. Doing all of these things will contribute to better overall heart health.

If the arrhythmia needs treatment it may include medication and/or interventions. Your treating specialist will discuss these options with you if required.

Doctor or psychiatrist consulting and diagnostic examining stressful woman patient on obstetric – gynecological female illness, or mental health in medical clinic or hospital healthcare service center

What's next

See your GP promptly if you’re experiencing any symptoms of arrhythmias, or if you have a referral, click here to find a cardiologist near you.

Our Doctors

This information is of a general nature. If you are concerned about your heart health, discuss this with your local doctor