Machines to restart a heart in cardiac arrest are often required by law in fitness clubs, but a new study found that people's hearts more commonly stop in places that are home to alternative forms of exercise.
Researchers found the employees of indoor tennis facilities, ice arenas and bowling alleys in and around Seattle were more likely to have to respond to someone in cardiac arrest, compared to those at health clubs and fitness centers.
"You've got higher site incidence at those three areas. That's kind of interesting. If we're legislating AEDs to traditional fitness clubs, shouldn't they be legislated to the others?" Dr. Richard Page, the study's lead author and chair of the department of medicine at the University of Wisconsin School of Medicine and Public Health in Madison, said.
AEDs - or automated external defibrillators - are portable devices that send electronic shocks to a heart in cardiac arrest, which occurs when the heart suddenly stops beating.
Approximately 300,000 people in the U.S. go into cardiac arrest every year and about 90 percent of those die, according to the Centers for Disease Control and Prevention (CDC).
Quick use of an AED, however, can increase a person's chance of survival.
For example, the CDC has found that about one in 10 people who go through cardiac arrest survive to be released from the hospital, but that rate climbs to one in three among those who were shocked by an AED during cardiac arrest.
The American College of Sports Medicine and the American Heart Association in 2002 encouraged all health and fitness facilities to have AEDs available, because the risk of cardiac arrest increases during and immediately after physical activity among those who don't regularly exercise.
For the new study, Page and his colleagues used registries from King County in the state of Washington to see how many cardiac arrests occurred in public indoor locations between 1996 and 2008.
Overall, there were 865 cases during that time. Of those, 16 didn't include information about their locations. Of the remaining 849, 52 occurred at fitness or health clubs and 84 at alternative exercise facilities, including bowling alleys, ice arenas and tennis facilities. The other cardiac arrests occurred in other public indoor spaces, such as community centers.
Based on those data, the researchers found that a fitness club's employees can expect to respond to one cardiac arrest every 42 years. That compares to one case every 11 years at a tennis facility, one case every 13 years at an ice arena and one case every 27 years in a bowling alley.
Dr. Stephen Meldon, vice chair of the Cleveland Clinic's Emergency Services Institute, said those facilities with higher rates may want to consider getting AEDs and training their staff in cardiopulmonary resuscitation - or CPR, which increases a cardiac arrest victim's chance of survival by moving blood around until a defibrillator is used.
"If you look at the annualized rates, they're still not remarkably frequent, but at the same time one life is worth one life," Meldon, who wasn't involved with the new study, said.
Page and his colleagues found that 83 percent of cardiac arrests at fitness and health centers were treated with CPR and publicly accessible AEDs, compared to 25 percent at the other sports facilities and community centers.
What's more, 56 percent of people who went into cardiac arrest in fitness facilities survived. That compared to 45 percent in the alternative exercise facilities and 34 percent in the other indoor public spaces.
But those rates, the researchers write in the Journal of the American College of Cardiology, may not apply to the rest of the country because King County is known for its fast emergency response times and high survival rates for cardiac arrests.
Also, Page said the lower incidence and higher survival rates at fitness clubs may be partially explained by selection bias because the people at those facilities may be healthier than those at bowling alleys.
He said he can't make the decision to install AEDs in bowling alleys and other facilities, but he'd want to be prepared.
"If you look at the individual sites where these are occurring, if you are putting them in fitness clubs, you should really be putting them in other places," he said.