DALLAS, June 2 -- It's not necessarily how many automated external defibrillators (AEDs) are available in a community, it's where they're located that may improve the success rate of restarting stalled hearts, according to a study.
In a report in today's Circulation: Journal of the American Heart Association, researchers in Seattle say taking time to plan where to place AEDs -- which are used to "shock" hearts back to life after they've stopped -- may help save lives.
In their study of commercial and civic establishments in the Seattle-King County area, researchers found the incidence of cardiac arrest was higher in airports, county jails, shopping malls and public sports stadiums and arenas. While researchers say it's not clear why cardiac arrests are more likely to happen in these places, they add that examining the data helps determine where AEDs are most likely to be needed.
Between January 1990 and December 1994, a total of 7,185 cardiac arrests were recorded in the Seattle and King County area. Of those, 1,130 occurred in public places with about half of that total occuring in automobiles and outdoors.
According to the study, placing 276 AEDs in the 172 higher-incidence sites would have provided treatment for 134 cardiac arrest patients over a five-year period. To cover the 347 cardiac arrests occurring in other public places -- hotels, buses, taverns, etc. -- over the same period, AEDs would have had to have been placed at approximately 71,000 sites, excluding outdoors and in automobiles.
"Placing defibrillators in public locations is a reasonable strategy, but probably only in locations with a relatively high incidence of cardiac arrest," says the study's lead author, Linda Becker, M.A., of the emergency medical services division of the Seattle-King County Department of Public Health. "We suggest that each community identify those sites with a high incidence of cardiac arrest to plan for rational placements of AEDs."
Co-authors of the report are Mickey Eisenberg, M.D., Ph.D.; Carol Fahrenbruch, M.S.P.H.; and Leonard Cobb, M.D.