THURSDAY, May 5 (HealthDay News) -- You stand a better chance of survival if your heart stops beating while you're in an exercise facility than if you're in another type of indoor public place, a new study found.

Overall, 50 percent of cardiac arrest victims survived if the attack occurred in a public place where some sort of exercise was happening, whereas only 36 percent of those who experienced cardiac arrest in other indoor public places survived. Exercise facilities included places traditionally thought of, such as gyms and fitness clubs, as well as places considered alternative exercise venues, such as bowling alleys and dance studios.

"Survival from sudden cardiac arrest with prompt resuscitation can really be quite high at exercise facilities," said lead researcher Dr. Richard L. Page, a cardiac electrophysiologist and chairman of the Department of Medicine at the University of Wisconsin. "That relates to the fact that people are healthier, they're feeling fit enough to go exercise, and they had a higher likelihood of CPR."

"We shouldn't just be deploying [automated external defibrillators] at fitness clubs," Page said. "We ought to consider less traditional exercise facilities as having patients at risk who could benefit from prompt resuscitation."

Though it's often confused with heart attack, sudden cardiac arrest is actually a different phenomenon.

Heart attack is a "plumbing problem," Page said. A blockage in the vessels of the heart cuts off blood flow, and part of the heart muscle dies. In some cases, a cardiac arrest can also occur.

Sudden cardiac arrest, Page explained, is caused by a disruption in the heart's electrical system. "You're unconscious within seconds and you're dead in 10 minutes if you don't get CPR and a defibrillation," he said. "The chance of survival is only a couple percent if you can't get immediate attention."

The goal of defibrillation is to reset the heart so it will return to a normal rhythm.

In their research, Page and his colleagues studied where cardiac arrests occurred in the Seattle area -- in indoor public places only -- between 1996 and 2008. They found 960 cases, 150 of which occurred at exercise facilities.

In the exercise facilities, 90 percent of the victims were men, 77 percent got CPR, 16 percent were treated with an automatic defibrillator machine and 50 percent survived.

Elsewhere in indoor public places, 75 percent of victims were men, 55 percent got CPR, 7 percent were treated with an automatic defibrillator machine and 36 percent survived.

At the exercise facilities, researchers found that 16 percent of the cardiac arrest sufferers were playing basketball, 9 percent were dancing, 9 percent "working out," 8 percent were on a treadmill and 8 percent each were playing tennis, bowling, swimming or weight lifting.

Though exercise is good for you overall, it does raise the risk for cardiac arrest, said Page, former president of the Heart Rhythm Society.

When asked why bowling alleys have so many cases of cardiac arrest, considering that bowling isn't a high-impact form of exercise, Page said the answer might lie in the fitness of bowlers and the atmosphere at a bowling alley, where people may be drinking alcohol.

He suggested that automatic defibrillators, which are often required in certain public places, should be placed in bowling alley s and dance studios, too. The machines typically cost $2,000 to $3,000.

Dr. Byron K. Lee, director of the electrophysiology laboratories and clinics at the University of California, San Francisco, said that though the study was interesting, it did not say whether the various physical activities boosted the risk for cardiac arrest over "baseline." Nor, he said, did it provide enough information to confirm whether the risk is high enough to warrant defibrillators in those places.

The study was to be presented Thursday in San Francisco at an annual meeting of the Heart Rhythm Society. Experts note that research presented at meetings should be considered preliminary because it has not been subjected to the rigorous scrutiny given to research published in medical journals.

More information

The U.S. National Heart, Lung, and Blood Institute has more on defibrillators.