People who suffered cardiac arrest and received chest compressions from bystanders had higher survival rates than those given standard resuscitation that included mouth-to-mouth breathing, a new study found.

About 300,000 people in the U.S. collapse each year from cardiac arrest, which can be brought on by a heart attack or other reasons, and fewer than one-third get CPR from bystanders, according to American Heart Association estimates. The breathing part of CPR is a big barrier for many people, the AHA says.

Growing...