PORTLAND, Maine — Ambulance crews and firefighters in Portland say a new system that changes the way they treat cardiac arrest victims has raised the survival rates of people whose hearts stop beating properly.

In a year survival rates have risen from about 5 percent to more than 17 percent.

The new system calls on emergency rescue workers to administer cardiopulmonary resuscitation chest compressions at the scene, rather than first carrying the victim to an ambulance.

In addition, all seven of the city’s ambulances have been fitted with new $35,000 automated external defibrillators, which guides firefighters to achieve the proper depth and rate of chest compressions.

Deputy Fire Chief David Jackson tells the Portland Press Herald everything available in the emergency room is now available in the ambulance.