⚠️Call Triple Zero (000) immediately if you think someone is having a heart attack or is in cardiac arrest.
5 min read
Cardiac arrest happens when the heart's electrical system stops working properly, causing the heart to suddenly stop beating. This prevents blood from reaching the brain and other vital organs. If not treated within minutes, it can quickly lead to death.
Cardiac arrest is usually caused by an electrical malfunction in the heart. Common causes include:
There may not always be a definite underlying cause for a cardiac arrest to occur. While it is more common for people over 70, cardiac arrest can happen to anyone, anywhere and at any time.
A cardiac arrest happens suddenly and rapidly. It often occurs with no warning. The person in cardiac arrest will:
A cardiac arrest is very different to a heart attack. During a heart attack, the person is conscious, breathing and can call out for help.
During a cardiac arrest, the person is not conscious, not breathing normally or at all, and cannot cry out for help.
Sometimes a heart attack can lead to a cardiac arrest. If you or someone is having a suspected heart attack, getting help as soon as possible can help prevent a cardiac arrest.
Heart attack | Cardiac arrest |
---|---|
Blocked artery prevents oxygen-rich blood from reaching the heart. | The heart suddenly stops beating due to an electrical problem. |
The person is usually conscious and breathing. | The person is unconscious and not breathing normally. |
Symptoms include chest pain, shortness of breath and nausea or vomiting. | Symptoms include sudden collapse, no response and not breathing (or not breathing normally). |
Call Triple Zero (000) and seek medical help immediately. | Call Triple Zero (000), start CPR and use an AED immediately. |
Read more about the warning signs of a heart attack. | Learn more about the differences between heart attack and cardiac arrest |
If you think someone is in cardiac arrest, follow Call, Push, Shock:
1. Call Triple Zero (000)
Call emergency services immediately. The operator will guide you through CPR and how to use an AED if there’s one available.
2. Push – start CPR
Press hard and fast in the centre of the chest (100–120 compressions per minute). Do not stop until help arrives or an AED becomes available.
3. Shock – use an automated external defibrillator
Any attempt at resuscitation is better than none.
CPR is a combination of mouth-to-mouth rescue breathing and chest compressions.
CPR helps to keep blood and oxygen circulating to the brain of a person whose heart has stopped beating, until the heart can be restarted.
CPR alone does not restore a normal heart rhythm. It does help keep the heart in a state where the AED has a greater chance of being able to do its job.
Compressions-Only CPR (COCPR) is CPR without rescue breaths (also known as ‘hands only CPR’). Both types of CPR double the person’s survival rates.
Remember, any attempt at resuscitation is better than none.
CPR alone does not restore a normal heart rhythm. It does help keep the heart in a state where the AED has a greater chance of being able to do its job.
An AED is a portable device that detects life-threatening abnormal heart rhythms and delivers an electrical shock if needed.
AEDs detect if the heart has a shockable rhythm. They only deliver a shock if required— an AED will not shock someone when a normal heartbeat is detected, or there is no heartbeat at all.
When both CPR is performed and an AED is used within the first 3 to 5 minutes of a sudden cardiac arrest, survival rates can increase 60-70%.
Having more AEDs in public places and awareness of their use can help save more lives.
After resuscitation, your healthcare team will:
Many survivors go on to live healthy, fulfilling lives.
You might like to join our MyHeart MyLife online community to connect with people across Australia who are on a similar recovery journey.
Watch David’s cardiac arrest survivor story:
Heart of the Nation has become a flagship program in the Heart Foundation to help save more hearts from sudden cardiac arrest.
For more information or to learn more about how you can get involved, head here.
Victoria Ambulance. Victorian Ambulance Cardiac Arrest Registry: 2021-2022 Annual Report. 2023. Available from: https://www.ambulance.vic.gov.au/wp-content/uploads/2023/03/VACAR-2021-2022-Annual-Report.pdf
Stiles MK, Wilde AAM, Abrams DJ et al. 2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families. Heart Rhythm. 2021;18(1):e1-50. doi:10.1016/j.hrthm.2020.10.010
Bray J, Howell S, Ball S et al. The epidemiology of out-of-hospital cardiac arrest in Australia and New Zealand: A binational report from the Australasian Resuscitation Outcomes Consortium (Aus-ROC). Resuscitation. 2022;172:74-83. doi: 10.1016/j.resuscitation.2022.01.011
Riva G, Ringh M, Jonsson M et al. Survival in out-of-hospital cardiac arrest after standard cardiopulmonary resuscitation or chest compressions only before arrival of emergency medical services. Circulation. 2019;139(23):2600-2609. doi: 10.1161/CIRCULATIONAHA.118.038179
Australian Resuscitation Outcomes Consortium. Annual Report. 2024. https://www.ausroc.org.au/wp-content/uploads/2025/01/Epistry-Annual-Report-2022-data-changes-07.01.25.pdf
Learn the difference between heart attack and cardiac arrest, their symptoms, survival rates, and prevention tips to help you respond in an emergency.
Particularly in the case of sudden cardiac arrest, because this is when someone’s heart abruptly stops beating, for no apparent or obvious reason.
Learn what an AED is and what you can do during a cardiac arrest.
Last updated07 July 2025
Last reviewed23 June 2025