Published 1 May 2025 · For Life First Aid
Many people think a heart attack and cardiac arrest are the same thing — but they are very different medical emergencies. Understanding the difference could help you recognise the signs and take the right action quickly.
A heart attack happens when blood flow to part of the heart is blocked.
The person is usually conscious and breathing.
A cardiac arrest happens when the heart suddenly stops beating.
This is a life-threatening emergency that requires immediate CPR and use of a defibrillator.
| Heart Attack | Cardiac Arrest |
|---|---|
| Caused by blocked blood flow | Caused by an electrical problem in the heart |
| Person is usually awake | Person is unconscious |
| Breathing continues | Breathing stops or becomes abnormal |
| Needs urgent medical care | Needs immediate CPR and AED |
Every second counts. Read our full guide on what to do if someone collapses.
A heart attack can sometimes lead to cardiac arrest. This is why recognising symptoms early is so important — acting quickly at the heart attack stage can prevent a situation from becoming worse.
Acting quickly can double or triple survival chances.
No — but they are closely related. A heart attack is a circulation problem; cardiac arrest is an electrical problem.
Not unless the person becomes unresponsive and stops breathing. If that happens, it has progressed to cardiac arrest — start CPR immediately.
Yes — and it can happen suddenly. This is why it is important to stay with the person and monitor them closely while waiting for emergency services.
Knowing the difference is important — but knowing what to do is even more critical. On our Cardiac First Responder Course, you will learn:
Heart attacks and cardiac arrests are both serious — but they require different responses.
Recognising the signs and acting quickly could save someone's life.
If you want to feel confident responding to real emergencies, get in touch or learn more about the course. Practical training, expert guidance, and the skills to make a real difference.