Watch: 'Time is absolutely crucial' – new app aims to save precious seconds after person suffers cardiac arrest

Only one in six people suffering from cardiac arrest in New Zealand will survive, but a new app called GoodSAM is hoping to change that.

Wellington Free Ambulance's Vanessa Simpson says the GoodSAM app is a play on 'Good Samaritan', but it also stands for 'good smartphone-activated medic'.

"Essentially, it alerts people who register and sign up on that app to a cardiac arrest that's happening within a kilometre radius of them," Ms Simpson said.

The app works by sending an alert to a registered member's phone.

If the alert is accepted, the location of the person in need is received and the user can then find them and perform CPR.

St John's Tony Smith says the first five minutes after a cardiac arrest is the most crucial.

"If a person gets CPR and the use of an AED or defibrillator in the first five minutes, their chance of surviving is more than doubled and that's why the use of bystanders is so crucial to outcomes following cardiac arrest," Mr Smith said.

The app also shows the location of the nearest defibrillator, which is just as crucial as CPR.

"It's crucial because CPR causes blood to flow around the body but it won't start the heart on its own, and a heart which has stopped beating needs both CPR and a defibrillator in order to be restarted," he explained.

GoodSAM sends an alert to the mobile phone of people who sign up, pointing them in the direction of people in desperate need. Source: Seven Sharp