First aid-trained Victorians could soon be called to handle triple-0 medical emergencies via a new mobile phone app.

Under the plan being developed by Ambulance Victoria, the app would notify the "trusted respondents" when somebody nearby had suffered a heart attack.

Responders would be notified when someone nearby was having a heart attack. Credit: supplied

The responders would be given the location of the patient and sent to provide CPR, as well as being alerted to the location of the nearest public defibrillator.

Paramedics would simultaneously be sent to treat the patient.