6 Things You Should Know About Heart Attacks and Sudden Cardiac Arrest
When it comes to heart emergencies, knowing the difference between a heart attack and sudden cardiac arrest could save a life – even your own.
Yet many Australians don't realise how different these two conditions are until they're faced with a real-life emergency.
Here’s what you need to know to be ready when every second counts.
1. They’re not the same thing
Although they both involve the heart, the causes and treatments are very different:
A heart attack is a circulation problem and happens when blood flow to part of the heart muscle is blocked, often by a clot.
A sudden cardiac arrest, on the other hand, is an electrical problem, where the heart's rhythm stops abruptly, preventing it from pumping blood at all.
A heart attack may sometimes lead to cardiac arrest, but they are separate medical emergencies.
2. Cardiac arrest is far more likely to be fatal
Each year, around 30,000 Australians experience an out-of-hospital cardiac arrest and, sadly, less than 10% of cardiac arrest patients survive.
- A heart attack may develop over hours or days.
- A cardiac arrest can cause death within minutes if no action is taken.
Acting fast matters. Bystander intervention with CPR and defibrillation can significantly improve the chances of survival.
3. Recognising the signs could save a life
Here’s how to tell them apart quickly:
Heart Attack Symptoms
- Chest pain or discomfort
- Shortness of breath
- Nausea, dizziness, sweating
- Pain radiating to the arms, neck, or jaw
Cardiac Arrest Symptoms
- Sudden collapse
- Unconsciousness
- No pulse
- No breathing or abnormal breathing
If in doubt, always call Triple Zero (000) and be prepared to start CPR if they become unresponsive and stop breathing normally.
4. What to do in a cardiac arrest
When someone's heart has stopped beating normally, early CPR and defibrillation are critical.
- Call Triple Zero (000) immediately.
- Start CPR: Push hard and fast in the
centre of the chest. - Use a defibrillator (AED) if one is available.
Time is everything.
Every minute without CPR or defibrillation drops a persons chance of survival by up to 10%.
DID YOU KNOW?
If CPR is started early, a person is up to 8x more likely to have a shockable heart rhythm that responds to defibrillation.
5. What to do in a heart attack
If someone is experiencing symptoms of a heart attack:
- Call Triple Zero (000) without delay.
- Keep them calm and still. Encourage them to sit or lie down.
- Loosen tight clothing to make breathing easier.
Don’t attempt CPR or defibrillation unless they lose consciousness and stop breathing normally – that's when it shifts to a cardiac arrest situation.
6. Why first aid training makes all the difference
First Aid training equips you with the skills and confidence to respond effectively to both heart attacks and cardiac arrests.
Without proper training, trying to follow emergency instructions over the phone can be overwhelming.
Having the right skills beforehand means you can step in, stay calm, and potentially save a life when every second counts.
Learning CPR and how to use a defibrillator doesn’t just help strangers – it could help your family, friends, or colleagues.
The Bottom Line
Understanding the difference between a heart attack and sudden cardiac arrest could make you the difference between life and death.
Minutes matter.
Get trained, stay prepared, and help save lives.
How to better prepare yourself
Medical emergencies can happen to anyone, anytime, anywhere.
Empower yourself to learn life-saving skills and take a first aid training course. Did you know it’s recommended Australians refresh their Provide First Aid training every 3 years, and CPR every 12 months?
With over 50+ venues across the state, click here to find your local St John Training Venue to refresh your First Aid training.
St John Ambulance NSW Training Venues
Publicly accessible AEDs are lifesaving assets in our communities.
Did you know that a defibrillator is the only device proven to increase the chances of survival after sudden cardiac arrest?
If you live in NSW and have a defibrillator at your workplace or on private property, make sure it's listed on the AED registry. Registering your device helps emergency services and the public locate it quickly when every second counts—and it's a great way to stay informed about where the nearest AED is in your area.
Modern AED’s are easy to use, even for untrained bystanders with most devices providing voice prompts to guide users through step-by-step process. For example, the St John Ambulance G5 AED features RescueCoach® and ICPR Technology, which provides real-time, guideline-based feedback on chest compression quality, helping ensure CPR is as effective as possible.
Click here to find out more about the St John Ambulance Defibrillator range.
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Quick Facts
- Coronary heart disease (which causes most heart attacks) is the leading single cause of death in Australia. It is responsible for about 10% of all deaths.
Source: ABS Causes of Death, 2023 - Around 30,000 out-of-hospital cardiac arrests occur in Australia each year. Source: St John Ambulance Victoria, 2023
- Men are more than 2x as likely to experience heart attacks compared to women, however, symptoms in women can be misdiagnosed as they can present with less typical symptoms.
Source: AIHW, 2024 - Sudden cardiac death accounts for over 1 in 4 deaths among Australians under 50.
Source: Heart, Lung and Circulation Journal, 2024