Immediate Response: Suspected Cardiac Arrest

The Chain of Survival describes four key, inter-related steps, which if delivered effectively and in sequence, optimise survival from out-of-hospital cardiac arrest.

1. Early recognition and call for help

If untreated, cardiac arrest occurs in a quarter to a third of patients with myocardial ischaemia (heart attack) within the first hour after onset of chest pain.

Once cardiac arrest has occurred, early recognition is critical to enable rapid activation of the ambulance service and prompt initiation of bystander CPR.

2. Early Bystander CPR

The immediate initiation of bystander CPR can double or quadruple survival from out-of-hospital cardiac arrest. Despite this compelling evidence, only 40% of victims receive bystander CPR in the UK.

3. Early Defibrillation

Defibrillation within 3 – 5 minutes of collapse can produce survival rates as high as 50 – 70%. This can be achieved through public access defibrillation, when a bystander uses a nearby AED to deliver the first shock. Each minute of delay to defibrillation reduces the probability of survival to hospital discharge by 10%. In the UK, fewer than 2% of victims have an AED deployed before the ambulance arrives.

4. Early advanced life support

Advanced life support with airway management, drugs and the correction of causal factors may be needed if initial attempts at resuscitation are unsuccessful. This and other post resuscitation care will be undertaken by the Ambulance Service and hospital cardiac specialists.

Central chest pain, ache or 'heavy' feeling in the chest; or a mild chest discomfort that makes the person feel generally unwell. This may feel like bad indigestion.

• This may spread to arms, neck, jaw, back or stomach.
• They may also feel light-headed, dizzy and short of breath, feel nauseous or vomit.

If you think they might be having a heart attack:

Call 999 or 112 for an ambulance.

Get them to sit down. Keep them calm. Don't give them any food or drink.

If untreated, cardiac arrest (see below) occurs in a quarter to a third of patients with myocardial ischaemia (heart attack) within the first hour after the onset of chest pain.