Cardiac arrest is when someone’s heart stops pumping blood around the body and they stop breathing normally. It is possible to survive and recover from a cardiac arrest, if you get the right treatment quickly.
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.
Someone who is having a cardiac arrest will suddenly lose consciousness and will stop breathing or stop breathing normally.
Giving an electric shock through the chest wall, by using defibrillator is the only way a person can recover from a cardiac arrest. 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.
A defibrillator cannot be used when there is no heart rhythm. Unless immediately treated with CPR(cardiopulmonary resuscitation) a cardiac arrest always leads to death within minutes. Performing CPR keeps the blood flowing to vital organs such as the brain and increases the chances of the heart remaining in a ‘shockable’ rhythm until a defibrillator is used. Every minute without CPR and defibrillation reduces the chances of surviving by up to 10 per cent.
There are a few simple steps that anyone witnessing, or finding someone that has had, a cardiac arrest can take to help save their life: calling 999, performing CPR and using a PAD (public access defibrillator) if one is available.
Recognising that someone is having a cardiac arrest and calling 999 is vital to ensure that the emergency services arrive as soon as possible. In some cases using a defibrillator will shock the heart and restore a normal rhythm. Effective post-resuscitation care is provided by the emergency medical services and transfer to acute care.
How to use a defibrillator
Defibrillators are very easy to use. Although they don’t all look the same, they all function in broadly the same way. The machine gives clear spoken instructions. You don't need training to use one.
If you come across someone who is not breathing or breathing erratically, the most important thing is to call 999 and start CPR to keep the blood flowing around the body. After a cardiac arrest, every minute without CPR and defibrillation reduces someone's chance of survival by 10 per cent.
If you're on your own, don't interrupt the CPR to go and get a defibrillator. If it's possible, send someone else to find one. When you call 999, the operator can tell you if there's a public access defibrillator nearby.
Once the defibrillator is open and in position, all you have to do is follow the spoken instructions. The defibrillator detects the heart's rhythm, it won't deliver a shock unless one is needed.
There’s lots more information about obtaining and using defibrillators in the Guide to Defibrillators we produced in conjunction with the Resuscitation Council UK.
If you've installed a defibrillator in your community or workplace, check that your ambulance trust knows about it. That way, 999 operators can quickly identify a nearby device in future emergencies.
Funding for defibrillators
Due to high demand our part-funding programme for a public access defibrillator and CPR training kit is currently closed.
If further funding does become available we’ll keep this website updated so please do check back.