People who suffered cardiac arrest and received CPR from a bystander were far more likely to return to work and full function than those who did not get help, according to a new study.

The research underscores the benefit of having bystanders trained in CPR, which these days can entail only chest compressions and be learned in a matter of minutes, said Don Weisman, American Heart Association communications director for Hawaii.

The study, Return to Work in Out-of-Hospital Cardiac Arrest Survivors, was published May 4 in Circulation, the medical journal of the Heart Association. It tracked the progress of 4,354 patients in Denmark who were employed when they suffered cardiac arrest between 2001 and 2011.

Those who received CPR from a bystander had a 38 percent greater chance of returning to work than those who didn’t. While previous research has shown that cardiopulmonary resuscitation boosts survival rates, this study went further in examining whether survivors returned to a normal life.

"When a bystander performs CPR quickly, it helps ensure enough oxygen is getting to the brain, which can help minimize brain damage and lead to that person being able to return to work," said the study’s lead author, Kristian Kragholm, a physician and clinical assistant at Aalborg University Hospital in Aalborg, Denmark, and a fellow at the Duke Clinical Research Institute in Durham, N.C.

Cardiac arrest is a sudden malfunction in the heart’s electrical system, which can strike otherwise healthy people at any time and is usually fatal. Victims of cardiac arrest collapse, stop breathing and become unresponsive.

A heart attack, on the other hand, involves blockage of blood flow to the heart. Its victims usually are conscious and complain of symptoms such as pain, tightness or weight on their chest.

"A heart attack is a plumbing problem, and cardiac arrest is an electrical problem," said Weisman. Bystanders should call 911 in either case and perform CPR if the patient is not responsive, he said.

About 420,000 cardiac arrests occur outside hospitals in the United States each year, and 90 percent of victims die, according to the American Heart Association. CPR can double survival rates, but observers often hesitate to intervene because they don’t know how or are afraid of hurting the victim, the association says.

"CPR today is so easy to learn," Weisman said. "The Heart Association a couple of years ago came out with new science showing that Hands-Only CPR is the most effective for lay people in saving lives."

"You don’t have to breathe on the victim, which was always a potential roadblock," he said. "It’s better to just do the chest compressions. The key is to call 911 first so you can get firefighters, police or ambulance on their way, and they’ll bring a defibrillator."

In Hawaii, rates of bystander intervention and recovery are lower than the U.S. average, according to Dory Clisham, training manager for American Medical Response in Hawaii. Nationally the survival rate for cardiac arrest is 10.8 percent and rises to 32.5 percent if witnessed by a bystander who calls 911 and provides CPR. The Hawaii rates are 9 percent and 26.4 percent, respectively, she said.

"If somebody just does something, they could save a life," Clisham said. "If everyone was trained, they could buy time for that individual. When our first responders arrive with the defibrillator, it will make a huge difference on the save rates."

When a teen or an adult suddenly collapses and stops breathing or moving, observers should call 911 and push hard and fast in the center of the victim’s chest, to the beat of the classic disco song, "Stayin’ Alive," or at least 100 compressions per minute, Clisham said. For infants and children, the heart association still recommends CPR with compressions and breaths.

The heart association is working with the Hawaii Department of Education in the hope of adding CPR to the Hawaii high school health curriculum. It also offers free training to the community, with the next event scheduled for Wednesday in Kakaako. (See box.)

Most cardiac arrests occur at home, so the first person you are likely to save is going to be a loved one or a friend, Weisman said.

Denmark has pushed hard to boost knowledge of CPR. Since 2006 it has required people getting their driver’s licenses to be certified in basic life support. The decade-long Danish study found that outcomes improved after that.

Altogether, although just 18 percent of cardiac arrest victims in the study survived, 3 out of 4 of those survivors were able to return to work at full pay.

"The interesting thing about this study is that they are able to go back into the community and live normal lives," Clisham said. "They are neurologically intact."