Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Electrocardiogram (ECG)

4-minute read

If you suspect you may be having a heart attack, dial triple zero (000) and immediately ask for an ambulance.

Key facts

  • An ECG is a simple, painless test that measures your heart’s electrical activity.
  • Your doctor may recommend an ECG if you have symptoms such as chest pain or a racing heart.
  • If your ECG is abnormal, you may need further tests or treatment.

What is an ECG?

An ECG is a graph of your heart's electrical activity. It’s a simple, safe and painless test. There’s no risk of being electrocuted.

Why do I need an ECG?

Your doctor may recommend an ECG if you have chest pain, a racing heart or other heart problems.

An ECG can show if you are having or have had:

  • a heart attack
  • a stressed heart muscle, due to narrowing or blockages in your heart arteries
  • irregular heart rhythms
  • pericarditis (heart lining inflammation)
  • abnormal heart electrical pathways

How can I prepare for an ECG?

You don’t need to do anything special to prepare for an ECG. Before the ECG, you may have your chest, arm or leg hair shaved or skin cleaned so the electrodes stick on your body properly. If you are wearing a bra, you might be asked to take it off.

Who performs ECGs?

A nurse, ECG technician or a doctor will perform your ECG.

What happens during the ECG?

During an ECG, leads are attached to electrodes using sticky dots that are placed on your arms, legs and chest. The leads connect to a machine, which takes the reading.

illustration of a gastric bypass
The ECG electrodes must be placed on clean, dry, skin. Sometimes, you will need to have the area shaved to ensure good skin contact.

What are the different types of ECG?

Different types of ECG include:

  • Resting ECG: you lie still for a few minutes and breathe normally while the ECG is recorded.
  • Ambulatory ECG (also called a 24-hour ECG, or Holter monitor): you wear the leads and carry a monitor while you go about your usual activities for 24 hours.
  • A cardiac stress test: the ECG is recorded while you exercise on a treadmill. It checks for areas of heart muscle that struggle when stressed. If you cannot exercise, medicines might be used to test the effect of stress on your heart.

If you have chest pain or another problem during the ECG, it’s important to tell the technician doing the test.

If you're having an ambulatory ECG, the technician may give you a diary to record of any symptoms.

What happens after my ECG?

A trained doctor or nurse will look at the ECG pattern and interpret what it says about your heart. Your doctor will discuss the results with you. If your doctor notices a serious problem in your ECG, you may need to begin treatment. Sometimes you may need other tests, like an ultrasound of your heart (echocardiogram), blood tests or an angiogram (pictures of the heart's blood vessels).

Should I use a smartphone or smartwatch ECG application?

Some heart problems are challenging to diagnose if your symptoms don’t occur while you’re having the ECG. Some smartphone and smartwatches can reconstruct an ECG from your pulse waveform. This could be useful in diagnosing heart rhythm abnormalities, but the accuracy of these applications and devices isn’t known. There are studies that are checking this.

If you wear a smartphone or smartwatch regularly, you can mention this to your doctor, who may find the tracking information useful.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: July 2022


Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Electrocardiogram - ECG - MyDr.com.au

An electrocardiogram is a medical test, commonly called an ECG or EKG, that uses a machine to measure and record the electrical activity in the heart.

Read more on myDr website

ECG - St Vincent's Heart Health

Information about electrocardiograms (ECG).

Read more on St Vincent's Hospital Heart Health website

ECG test - Better Health Channel

A doctor may recommend an electrocardiogram for patients who may be at risk of heart disease because of family history, smoking, overweight, diabetes or other conditions.

Read more on Better Health Channel website

Arrhythmias (abnormal heart rhythms)

Arrhythmia is when you have an abnormal heart rhythm and heart palpitations are an awareness of your heartbeat.

Read more on WA Health website

Long QT syndrome - symptoms, causes and treatment

Find out about Long QT syndrome, and how an electrical problem in the heart can cause a very fast heart beat and sudden death.

Read more on myDr website

Monitor, devices and alarms - My Life After ICU

Some devices send information from body surfaces

Read more on Australian and New Zealand Intensive Care Society website

Wolff-Parkinson-White syndrome - Better Health Channel

Wolff-Parkinson-White syndrome is characterised by attacks of rapid heart rate or tachycardia.

Read more on Better Health Channel website

Cardiac MRI (Magnetic Resonance Imaging) | myVMC

Cardiac MRI scan Magnetic Resonance Imaging of human heart and brain etc with an MRI with services of an MRI machines

Read more on myVMC – Virtual Medical Centre website

Exercise stress tests - MyDr.com.au

Exercise stress testing assesses the performance and capacity of the heart during exercise and is used to help diagnose or investigate heart disease.

Read more on myDr website

Medical tests for heart disease | Heart Foundation

Common tests your doctor may want you to have which will help understand and manage your condition

Read more on Heart Foundation website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.