cardiac arrest happens when your heart stops pumping blood around
the body. The most common cause of a cardiac arrest is a life
threatening abnormal heart rhythm called ventricular
Ventricular fibrillation occurs when the electrical activity of
the heart becomes so chaotic that the heart stops pumping and
quivers or 'fibrillates' instead.
This is a cardiac arrest. It can sometimes be
corrected by giving an electric shock through the chest wall, using
a device called a defibrillator.
Some other reasons why you might have a cardiac arrest are:
- if you lose a large amount of blood or fluid
- lack of oxygen
- your body being very hot or very cold
- a blood clot in the lung or coronary arteries
A cardiac arrest is different from a heart attack.
A heart attack usually happens because you have coronary heart disease. If you have a heart
attack, you do not always experience the life threatening rhythms
that can lead to a cardiac arrest. A cardiac arrest does not
always happen because you have a heart condition.
If you have a cardiac arrest, you lose consciousness almost
There are also no other signs of life such as breathing or
This is an emergency and if you witness a cardiac
arrest you should call 999 immediately.
Cardiopulmonary resuscitation (CPR)
starts cardiopulmonary resuscitation
(CPR) the person may suffer permanent damage to the brain and other
- chest compression (pumping the heart by external cardiac
massage), to keep the circulation going until the ambulance arrives
- rescue breathing (inflating the lungs by using mouth-to-mouth
Ambulance staff are trained in advanced resuscitation and all
emergency ambulances carry a defibrillator.
For more information about saving lives and to find out about
our training courses visit our Heartstart page.