A cardiac arrest happens when your heart stops pumping blood around your body.
If someone has suddenly collapsed, is not breathing normally and is unresponsive, they are in cardiac arrest.
There is no time to lose. Even if you are untrained your actions can help.
Causes a cardiac arrest.
The most common cause of a cardiac arrest is a life threatening abnormal heart rhythm called ventricular fibrillation (VF).
Ventricular fibrillation happens when the electrical activity of your heart becomes so chaotic that the heart stops pumping and quivers or ‘fibrillates’ instead. There are various causes of VF. These can be problems with your heart, or other causes.
Can you recover from a cardiac arrest?
It is possible to survive and recover from a cardiac arrest, if you get the right treatment quickly.
VF can sometimes be corrected by giving an electric shock through the chest wall, by using a device called a defibrillator.
This can be done in the ambulance, or at hospital, or it can be done by a member of the public at the scene of a cardiac arrest if there is a community defibrillator nearby.
Immediate CPR can be used to keep oxygen circulating around the body until a defibrillator can be used and/or until the ambulance arrives.
Ref : British Heart Foundation