How You Can Help

If you see someone suddenly collapse, but you haven't had CPR training, call 911 before you do anything else.

Then, if it's an adult or teenager who collapsed during exertion, begin compression-focused CPR and send someone to find an automatic external defibrillator.

To do the compressions:

• Place your hands in the middle of the chest, one hand on top of the other.
• Push hard and push fast

"Don't worry about hurting them," said Dr. Michael Sayre, a co-author of the American Heart Association's new guidelines. "Injury is really uncommon."

"If an infant or a child suddenly collapses, the cause is much more likely to involve respiration," said Dr. Dana Peres Edelson, of the University of Chicago Medical Center, and ventilation may be more important. But again, if you don't have training, the American Heart Association recommends hands-only CPR.

"Doing something is always better than nothing, and chest compressions can buy time," Sayre noted.