The charity, in partnership with NHS England, is urging Londoners to become “community advocates” for their area and promote lifesaving skills.
Those who volunteer will receive free training in CPR and the use of defibrillators. They will be expected to share this knowledge with neighbours and the wider community for three hours a month.
Over 30,000 people in England suffer a cardiac arrest outside of hospital every year, but less than one in ten go on to make a full recovery. Every minute without CPR or defibrillation reduces the chance of survival by up to 10 per cent, according to the British Heart Foundation.
NHS England hope to increase survival rates by 25 per cent by 2028 through the network of community advocates.
Volunteers will also promote defibrillator locations and the importance of registering the devices onto The Circuit – the national defibrillator network.
Medical Director for St John Ambulance, Dr Lynn Thomas, said: “In a cardiac arrest the worst thing you can do is nothing. By starting chest compressions and applying a defibrillator, you could help increase the chances of survival.
“Basic first aid and lifesaving skills like CPR are easy to learn and could make all the difference in helping save a life of a loved one, colleague, or a passer-by in a life-threatening situation.”
Professor Sir Stephen Powis, NHS Medical Director said: “It is essential that there are people in the community who are equipped with the knowledge, skills and equipment they need to be able to save a life, and the NHS is proud to be working with St John and other partners to champion the importance of learning how to recognise and respond to out-of-hospital cardiac arrest.
“We know that if more people were able to deliver CPR until an ambulance crew arrives, find and use a defibrillator, the number of lives saved would double.”