What’s the difference?

Heart attack VS cardiac arrest:

Updated 2026- with new comparison table and section Can a Heart Attack Cause Cardiac Arrest?

Key Takeaway: A heart attack is caused by blocked blood flow to the heart, while a cardiac arrest is caused by an electrical failure that stops the heart beating. They are both life-threatening but are treated very differently.

Heart Attack vs Cardiac Arrest: Comparison Table

Feature	Heart Attack	Cardiac Arrest
What’s happening	Blood flow to part of the heart muscle is blocked	The heart’s electrical system fails
Type of problem	Circulation (plumbing) problem	Electrical rhythm problem
Is the heart beating?	Usually yes	No — the heart stops beating effectively
Is the person conscious?	Often awake (may worsen over time)	No — sudden collapse and unresponsiveness
Is the person breathing?	Usually breathing	Not breathing or only gasping
Speed of onset	Can build over minutes or hours	Happens suddenly, often without warning
Immediate first aid	Call 000, rest the person, assist with prescribed medication, give 300 mg aspirin	Start CPR immediately and use an AED
Can it lead to death?	Yes	Yes
Can one cause the other?	A heart attack can trigger cardiac arrest	Cardiac arrest is not always caused by a heart attack

Although the names sound similar, a heart attack and a cardiac arrest are very different emergencies, and knowing the difference can help you respond correctly in a real situation.

Why Knowing the Difference Matters

The terms heart attack and cardiac arrest are often used interchangeably, but they are not the same medical emergency. While the names sound similar, they have very different causes and require different responses.

If you’re unsure what separates them, you’re not alone. Below is a clear explanation of what each one means and how they differ in a real medical setting.

What Is a Heart Attack and What Causes It?

A heart attack — medically known as a myocardial infarction (MI) — occurs when the heart muscle is damaged due to reduced blood flow. This damage may affect a small area of the heart or a larger section, depending on how severe the blockage is.

For this reason, a heart attack is often described as a “plumbing problem.”

In most cases, it is caused by a blocked coronary artery. These are known as type 1 heart attacks, where cholesterol buildup in the artery ruptures and forms a clot, obstructing blood flow and triggering the heart attack.

an ai generated image of a clogged artery

What Is Cardiac Arrest and Why Does It Happen

Cardiac arrest is not caused by a blockage. Instead, it occurs when the heart’s electrical rhythm is disrupted, preventing the heart from beating effectively.

For this reason, cardiac arrest is often described as an electrical rhythm disturbance.

When a person has a cardiac arrest, the heart stops pumping blood around the body, cutting off oxygen to vital organs such as the brain and lungs.

This can happen within seconds and causes the person to stop breathing and become unresponsive, requiring immediate CPR and defibrillation.

What Causes Cardiac Arrest?
Causes and Risk Factors

An image showing cardiac arrest causes.
The first scene shows a person drowning in the sea. The second scene shows a car crash on the road. The third scene shows a person clutching their chest on the sidewalk. The fourth scene shows a person standing in the hot sun on a sidewalk. The fifth scene shows a young fit person working out at a gym.

Cardiac arrest can happen for a variety of reasons and can even occur in seemingly healthy individuals. It’s important to know that some heart attacks do cause a cardiac arrest and cause the heart to stop beating, but so many other things can also cause it.

Here’s a list of heart and non heart related causes, some might surprise you.:

Heart-Related Causes:
- Coronary artery disease: The narrowing or blockage of arteries reduces blood flow, potentially disrupting the heart’s electrical activity
- Heart attack (Myocardial infarction): Damage to the heart muscle can lead to life-threatening electrical disturbances.
- Cardiomyopathy: A thickened or enlarged heart muscle can cause irregular heart rhythms.
- Arrhythmias: Abnormal heart rhythms, such as ventricular fibrillation, can trigger cardiac arrest
Non-Heart-Related Causes:
- Trauma: Severe trauma, such as a car accident, can directly impact the heart’s rhythm.
- Drug Overdose: Stimulants (e.g., cocaine) can induce arrhythmias, leading to cardiac arrest
- Hypoxia (lack of oxygen): Drowning, suffocation, or respiratory failure deprives the heart of oxygen, affecting its function.
- Severe blood loss or dehydration: Causes hypovolemia, which impacts heart function.

Common Risk Factors Include:

Genetics: Certain conditions can run in families, making cardiac arrest more likely. Some people have suffered sudden arrests even at a young age. Due to genetic reasons a Cardiac Arrest can happen with no obvious warning signs
Lifestyle factors: Smoking, obesity, lack of exercise, and high alcohol intake increase risk.
Underlying conditions: High blood pressure, diabetes, and high cholesterol.

How much damage can a heart attack cause?

The amount of damage caused by a heart attack depends on how large the affected area is and how quickly treatment begins.

Doctors often measure troponin levels in the blood to estimate the extent of heart muscle damage, and may use an echocardiogram (heart ultrasound) to assess how well the heart is pumping.

Larger heart attacks can weaken the heart muscle and reduce its ability to pump effectively.

Common Signs and Symptoms of a Heart Attack

Symptoms of a heart attack may be subtle to severe, and may include one or more of the following:

Pain, pressure or squeezing in the chest area
Pain and discomfort in the arm, neck or back
Sudden shortness of breath
Sudden vomiting or feelings of nausea
Unexplained fatigue and dizziness
To find out more about joining a remote first aid course with our nationally recognised trainers, contact us now or, browse our upcoming sessions here.

a middle aged woman on queen st brisbane experiences a heart attack

Can a Heart Attack Cause Cardiac Arrest?

Yes — a heart attack can lead to cardiac arrest, but they are not the same thing.

During a heart attack, reduced blood flow can damage the heart muscle. In some cases, this damage interferes with the heart’s electrical system and causes the heart to suddenly stop beating, resulting in cardiac arrest.

However, many heart attacks do not progress to cardiac arrest. A person may remain conscious and breathing, experiencing chest pain or discomfort, without the heart stopping.

Because it’s impossible to predict who will deteriorate, it’s good to get a defibrillator to the scene as soon as possible.

What Is the Correct First Aid for a Heart Attack?

Stop what the person is doing and help them rest comfortably, seated or lying down

Call 000 immediately for an ambulance

Assist with any prescribed medication (such as angina spray)

Give 300 mg aspirin (unless the person is allergic)

Stay with the person, keep them calm, and follow instructions from the emergency operator

If the person collapses, becomes unresponsive, or is not breathing normally, start CPR and follow the DRSABCD action plan until help arrives.

What Is the Correct First Aid for Cardiac Arrest?

hen someone has a cardiac arrest, immediate action is critical.

Ensure safety for yourself and the person
Call 000 immediately or send someone to call
If the person is unresponsive and not breathing normally, start CPR straight away
Perform chest compressions at 100–120 per minute
Give rescue breaths only if you are trained and confident — otherwise continue hands-only CPR
Use an AED as soon as it is available and follow the voice prompts

These steps follow the DRSABCD basic life support action plan, which outlines the correct order of response in an emergency. You can read our full DRSABCD guide here.

A man is positioned on the ground suffering a cardiac arrest. another man has hands placed on his chest, indicating CPR

Relevant Statistics

Heart Attack Statistics

Heart attacks are a leading cause of death in Australia, responsible for almost 1https://www.heartfoundation.org.au/your-heart/evidence-and-statistics/key-statistics-heart-attack in 25 deaths (around 4%) — that’s roughly one death every 80 minutes.
Men experience heart attacks more often than women, with significantly higher rates across most age groups.

Cardiac Arrest Statistics

In Australia, over 25,000 people experience an out-of-hospital cardiac arrest each year — nearly 70 people every day — with an average survival rate of around 10–12%.
Immediate CPR can double or even triple survival rates, particularly when started by bystanders before emergency services arrive.
Early use of an AED significantly improves survival, especially when defibrillation occurs within the first few minutes of collapse.

Learn more at a first aid or CPR course

Every second counts during an emergency, and knowing how to respond can be the difference between life and death.

The HLTAID009 Provide Cardiopulmonary Resuscitation (CPR) course equips you with the skills and confidence to respond effectively to cardiac arrest and basic emergency first aid situations. Whether it’s a sudden collapse, choking, or any life-threatening cardiac event, this course ensures you’re ready to jump into action with the right techniques.

But why stop there? Expand your life-saving abilities with the HLTAID011 Provide First Aid course. This comprehensive training covers everything from CPR and cardiac emergencies to managing wounds, burns, fractures, allergic reactions, and much more.

You’ll gain the skills to protect your loved ones, colleagues, or even strangers in need. Imagine being the person everyone turns to during an emergency—calm, prepared, and capable of saving lives.

Don’t just think about it—take action now! Become the hero your community needs. Enroll in HLTAID009 Provide Cardiopulmonary Resuscitation today, and consider elevating your skills even further with the HLTAID011 Provide First Aid course. Your journey to becoming a confident, capable first aider starts here!