LOS ANGELES - People who suffer a life-threatening alteration in heart rhythms are more likely to survive if they are in a casino or airport than if they are in a hospital, researchers reported yesterday.
Doctors already knew that more than half of those who suffer such attacks in airports and casinos survive.
But a study in hospitals shows that only a third of victims there survive - primarily because patients do not receive life-saving defibrillation within the recommended two minutes.
Nearly 40 percent of hospitalized patients who received defibrillation within two minutes survived to leave the hospital, compared to only 22 percent of those for whom the response took longer, researchers reported in the New England Journal of Medicine.
As many as 750,000 people suffer such attacks in hospitals every year in the United States and another 250,000 outside hospitals.
"It is probably fair to say that most patients assume - unfortunately, incorrectly - that a hospital would be the best place to survive a cardiac arrest," University of Southern California cardiologist Dr. Leslie Saxon wrote in an editorial accompanying the report.
People who suffer a heart attack in the middle of a crowded airport or casino - where defibrillators are widely available - are typically noticed immediately, whereas a lone patient suffering an attack in a hospital room may not be noticed for much of the crucial window of opportunity during which defibrillation is most effective.
The odds of survival are even lower in small hospitals with fewer than 250 beds, and on nights and weekends, according to the study by Dr. Paul Chan of Saint Luke's Mid-America Heart Institute in Kansas City, Mo., and Dr. Brahmajee K. Nallamothu of the University of Michigan.
At least part of the apparent discrepancy arises because hospitalized patients are sicker to begin with, while those who suffer attacks in airports and casinos generally don't have underlying medical illnesses or symptoms, said University of California, Los Angeles cardiologist Dr. Gregg Fonarow, who was not involved in the study.
Defibrillation is used when patients suffer either ventricular fibrillation or ventricular tachycardia. In the first case, the heart beats abnormally or intermittently, while in the second it beats extremely rapidly. In both cases, the result is the same: an inability to pump blood through the body effectively.
Applying a shock to the heart often restores normal heart rhythms. The devices found in public places, called automated external defibrillators, can be used by trained laymen.