A potentially life-saving smartphone app has been launched in South Australia to help people having a heart attack get access to help sooner.

The GoodSAM app will be used by SA Ambulance staff and volunteers before being rolled out to other health professionals, emergency services personnel and people with first aid training.

It sends an alert to registered users if there is a cardiac arrest near them.

The responder can accept the call for help and head to the scene to provide emergency care while an ambulance is on the way.

The system can identify if any responders are in the vicinity and alert the three closest.

If one or more of those responders accept the alert, it sends them the location details.

"Recruiting the help of those nearby is an important start in the chain of survival before an ambulance arrives and will save lives," Health Minister Chris Picton said.

First launched in the UK, GoodSAM is already in use in Victoria where there are already more than 11,000 registered responders.

"In cardiac arrest, seconds count. The GoodSAM network of volunteer responders provides basic life support to those nearby in cardiac arrest while an ambulance is on its way," founder Mark Wilson said.

"These off-duty heroes save many lives each year."

In the Adelaide CBD, GoodSAM will alert responders who are within 400 metres, while in the broader metropolitan area and regional cities, it will alert those within 600 metres.

In regional areas the response radius will be five kilometres for regional towns and up to 15 kilometres in more remote locations.

The SA ambulance service expects to issue more than 1100 alerts each year.