Heart attack vs cardiac arrest: what's the difference?

White writing on red background reads heart attack vs cardiac arrest. There is also an Illustration of a person holding his chest who is having a heart attack and an illustration of a person receiving CPR for a cardiac arrest.

Our animation explains the difference between a heart attack and a cardiac arrest and what to do in these emergencies.

What's the difference between a heart attack and a cardiac arrest?

A heart attack and a cardiac arrest are not the same condition.

A heart attack happens when there is a sudden loss of blood flow to a part of the heart muscle, while a cardiac arrest is when your heart suddenly stops pumping blood around your body.

A cardiac arrest is an electrical issue with the heart and the person affected will be unconscious, and a heart attack is a circulatory issue where the person is likely to be conscious.

Illustration showing a cardiac arrest is an electrical problem and a heart attack is a circulation problem

Is it a heart attack or a cardiac arrest?

A heart attack happens when the blood supply to the heart muscle is cut off.

This is often caused by a blood clot in one of the coronary arteries.

The heart is still pumping blood around the body during a heart attack. The person will usually be conscious and breathing.

A sudden cardiac arrest is when your heart stops pumping blood around your body.

It occurs when your heart's electrical system does not work properly and your heart starts beating too quickly, too slowly or irregularly.

This is an abnormal heart rhythm, called an arrhythmia.

Not all abnormal heart rhythms are life-threatening, but some mean that the heart cannot pump blood around the body.

The table below shows the key differences between a heart attack and cardiac arrest and what to do if you are present when they happen.

Heart attack	Cardiac arrest
Blood supply to the heart is cut off, often by a blood clot in one of the coronary arteries	The heart stops beating
The heart is still pumping blood, but if left untreated the heart muscle will begin to die as it is not getting enough oxygen	The heart is not pumping blood around the body, which deprives the brain of oxygen and this causes a sudden collapse
Person will usually be conscious and breathing	Person will be unconscious and unresponsive and they will not be breathing normally or at all, or making gasping noises
Call 999	Call 999 and start CPR

Heart attack symptoms

A heart attack is an emergency. Symptoms include:

pain or discomfort in your chest that happens suddenly and does not go away
pain that spreads to either arm, your neck, jaw, upper back or stomach
feeling sick, sweaty, light-headed or short of breath.

The pain can feel very bad, while for others it is more uncomfortable. It can feel like heaviness or a burning pain, similar to indigestion.

Other less common symptoms include:

suddenly feeling anxious, like a panic attack
lots of coughing or wheezing.

Heart attack symptoms are different for different people. You may not have all these symptoms.

A BHF senior cardiac nurse explains common heart attack symptoms to watch out for.

Our cardiac nurse explains the main signs and symptoms to be aware of, and when to call 999. 

Cardiac arrest symptoms

A cardiac arrest is an emergency that usually happens without warning.

If someone is in cardiac arrest, they collapse suddenly and:

will be unconscious
unresponsive
not breathing or not breathing normally or they may make gasping noises.

Do heart attacks cause cardiac arrest?

A heart attack can lead to a cardiac arrest as you are at higher risk of having ventricular fibrillation (VF), which is a deadly arrhythmia.

But heart attacks are not the only cause of a cardiac arrest.

How to help with a heart attack or cardiac arrest

Heart attack and cardiac arrest are different conditions, but they are both medical emergencies.

What do to if someone is having a heart attack	What to do if someone is having a cardiac arrest
Call 999 for an ambulance	Call 999 for an ambulance
The person should sit down and stay calm	Start CPR
They can chew aspirin, if they have it and are not allergic	Use a defibrillator if there is one nearby or ask someone to fetch the nearest one
Wait for the ambulance	Follow instructions from the 999 operator until emergency services take over

It's important to get immediate medical attention if you think you or someone you are with is having a heart attack.

If there is any delay, the person having the heart attack may suffer serious heart damage and is more likely to need intensive care and to spend longer in hospital.

If you are with someone who is having a cardiac arrest it is vital to call 999 and start immediate CPR as it keeps blood and oxygen moving around the brain and the body.

If you can access one, a defibrillator will then deliver a controlled electric shock to try to get the heart beating normally again.

Public access defibrillators are often in places like train stations and shopping centres. Anyone can use one and you do not need training.

You can learn how to identify a cardiac arrest and perform CPR in 15 minutes using BHF's free online RevivR tool.

If you are deaf and have an emergency, you can call 999 using a free BSL helpline.

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