MONDAY, Nov. 15 (HealthDay News) -- Although automated external defibrillators have been found to reduce heart attack death rates in public places such as restaurants, malls and airplanes, they have no benefit and, paradoxically, seem to increase the risk of death when used in hospitals, a new study suggests.
The reason may have to do with the type of heart rhythms associated with the heart attack, said researchers publishing the study in the Nov. 17 issue of the Journal of the American Medical Association, who are also scheduled to present their findings Monday at the American Heart Association (AHA) annual meeting in Chicago.
And that may have to do with how sick the patient is.
The authors only looked at hospitalized patients, who tend to be sicker than the average person out shopping or attending a sports event. In those settings, automated external defibrillators (AEDs), which restore normal heart rhythm with an electrical shock, have been shown to save lives.
"You are selecting people who are much sicker, who are in the hospital. You are dealing with heart attacks in much more sick people and therefore the reasons for dying are multiple," said Dr. Valentin Fuster, past president of the AHA and director of Mount Sinai Heart in New York City. "People in the street or at a soccer game are much healthier."
In this analysis of almost 12,000 people, only 16.3 percent of patients who had received a shock with an AED in the hospital survived versus 19.3 percent of those who didn't receive a shock, translating to a 15 percent lower odds of surviving.
The differences were even more acute among patients with the type of rhythm that doesn't respond to these shocks. Only 10.4 percent of these patients who were defibrillated survived versus 15.4 percent who were not, a 26 percent lower rate of survival, according to the report.
For those who had rhythm
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