Overland Park, KS — Installing automated external defibrillators (AEDs) in schools and public places could increase survival rates for sudden cardiac arrest (SCA), according to two studies published last month in the American Heart Association (AHA) journal Circulation.

However, for AEDs to be effective, plans for emergency response should be initiated and practiced annually, and public AED installation should be guided to avoid excess cost and promote the best coverage, the studies also found.

In one study, researchers examined 1,710 American high schools with AED programs in place. Of 36 cases of SCA between December 2006 and July 2007, the study found that 30 of the victims received an AED shock, and 23 of them survived to hospital discharge. This included nine of 14 student-athletes and 14 of 22 adults. However, although 83 percent of the schools studied had an emergency AED plan in place, only 40 percent practiced the plan annually.

In a separate Danish study, researchers found that almost 70 percent of cardiac arrests in public places could be covered by AEDs placed strategically within a city.

Scientists digitally marked locations in Copenhagen, Denmark, where SCA incidences occurred in public, then they analyzed the locations of the AEDs in relation to the sites. They also looked at effectiveness of European and American guidelines for public AED placement.

“If AED deployment in the community is driven by local or political initiatives and not on strategic AED placement, there is a high risk of AEDs being placed primarily in low-incidence areas of cardiac arrest and hence low likelihood of the AEDs ever being used,” wrote Fredrik Folke, M.D., lead author of the study