Experts say the findings, reported in an August issue of The New England Journal of Medicine, may trigger dramatic shifts in EMS funding to provide better access to AEDs throughout the country.

In one study, researchers tested the effect of launching a paramedics program in Canadian cities whose citizens were already trained in CPR and AED use. Data show that survival rates did not improve. In addition, more victims saved by bystanders survived with excellent brain function (78 percent) than those treated by paramedics (68 percent).

A second study, the Public Access Defibrillation trial, found that training volunteers to use AEDs placed in shopping centers and recreational facilities doubled the number of cardiac arrest victims who survived and were able to leave the hospital.

The Home Use AED Trial is now under way to prove the benefit of placing AEDs in homes, where the majority of cardiac arrests occur.