Cardiac Arrest

A cardiac arrest is when your heart suddenly stops pumping blood around your body. When your heart stops pumping blood, your brain is starved of oxygen. This causes you to fall unconscious and stop breathing.

Hero curve mask

What are the signs of a cardiac arrest?

A cardiac arrest usually happens without warning. If someone is in cardiac arrest, they collapse suddenly and:

  • will be unconscious
  • will be unresponsive and 
  • won’t be breathing or breathing normally – not breathing normally may mean they’re making gasping noises.

Without immediate treatment or medical attention, the person will die. If you see someone having a cardiac arrest, phone 0817-444-5544 immediately and start CPR.

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What causes a cardiac arrest?

A common cause of a cardiac arrest is a life-threatening abnormal heart rhythm called ventricular fibrillation (VF).

VF happens when the electrical activity of the heart becomes so chaotic that the heart stops pumping, Instead, it quivers or ‘fibrillates’.

The main causes of cardiac arrest related to the heart are:

  • heart attack (caused by coronary heart disease)
  • cardiomyopathy and some inherited heart conditions
  • congenital heart disease
  • heart valve disease
  • acute myocarditis (inflammation of the heart muscle).

Some other causes of cardiac arrest include:

  • electrocution
  • a drug overdose
  • a severe haemorrhage (known as hypovolaemic shock) – losing a large amount of blood
  • hypoxia – caused by a severe drop in oxygen levels. 

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

A heart attack and cardiac arrest are not the same.

A heart attack happens when the blood supply to the heart muscle is cut off. This is often caused by a clot in one of the coronary arteries. The heart is still pumping blood around the body during a heart attack. The person will be conscious and breathing.

A heart attack can lead to a cardiac arrest. It’s vitally important to get medical attention immediately by calling 999 for an ambulance if you experience heart attack symptoms. 

Graphic showing difference between a heart attack and a cardiac arrest

How is a cardiac arrest treated?

Starting immediate CPR is vital as it keeps blood and oxygen circulating to the brain and around the body. A defibrillator will then deliver a controlled electric shock to try and get the heart beating normally again.

Public access defibrillators are often in locations like train stations and shopping centres. Anyone can use one and you don’t need training to do so. 

Recovery after a cardiac arrest

Immediate recovery

After a cardiac arrest, you’ll have been looked after in a coronary care or intensive care unit. You may have been put in an induced coma and kept asleep to allow your body to recover. 

Mid-term recovery

Our Doctors and cardiologists will work with you to identify the cause of a cardiac arrest prior to recommending treatment, such as a pacemaker or implantable cardioverter defibrillator (ICD), to reduce the risk of it happening again. 

They may also refer you to cardiac rehabilitation to help rebuild your confidence, fitness and strength levels. Each programme is different, but it usually involves regular assessments such as checking your pulse and blood pressure, psychological support, health education talks and exercise sessions. 

Long-term recovery

It will take time to recover after a cardiac arrest, but your doctor will support you during this time. Talk to family and doctors about what will happen once you go home and practical matters, like driving and returning to work.

Your doctor may suggest making lifestyle changes to reduce your risk of another cardiac arrest. This can include:

  • eating a healthy diet
  • quitting smoking
  • cutting down on alcohol
  • being physically active.

Because of a lack of oxygen to the brain during a cardiac arrest, you might experience long-term effects to your brain. These can include:

  • personality changes 
  • problems with memory
  • fatigue
  • dizziness or balance issues
  • aphasia/dysphasia (problems with speech and language)
  • myoclonus (involuntary movements)
  • permanent brain injury.

It’s normal to have no memory of a cardiac arrest. This can be alarming for you and your family members who may have seen it happening.