You see someone suddenly fall to the ground, unconscious on the street or at a park. A quick check of the pulse shows the heart's not beating. Now what?
Of course, someone needs to call 911 for an ambulance. But odds are, the victim won't survive unless someone quickly starts performing cardiopulmonary resuscitation. Unfortunately, most people won't try.
While performing CPR is simpler than ever, knowledge about how to perform the lifesaving procedure is sketchy, even for many who once received training.
Researchers have found that only about 30 to 40 percent of people with no medical background will attempt resuscitation when they see someone in apparent cardiac arrest.
Sudden cardiac arrest occurs when electrical impulses in the heart become rapid or chaotic, causing the heart to suddenly stop beating. According to the American Heart Association, more than 380,000 sudden cardiac arrests happen outside a hospital each year, and 88 percent of these occur at home. Less than 8 percent of people whose heart stops beating outside a hospital survive.
CPR is no longer a complex juggle of chest compressions and rescue breaths. Since 2010, the standard has been to focus on the heart with rapid, steady pumps to the chest. You can skip the mouth-to-mouth.
Researchers know that getting effective CPR from a bystander doubles or triples a victim's chances of survival. But too few people know how, particularly in some neighborhoods, and even people with training may be reluctant to help.
A study published last fall in The New England Journal of Medicine looked at the race and neighborhood of more than 14,000 cardiac-arrest victims in 29 U.S. cities. Researchers found that people who suffer cardiac arrest in poor black neighborhoods are half as likely to get CPR from a bystander than people in better-off white neighborhoods. But those who did get CPR were twice as likely to survive to be discharged from a hospital than those who did not.
Survival rates for cardiac arrest outside a hospital ranged from a low of 0.2 percent in Detroit to 16 percent in Seattle, largely because of the difference in training and willingness of people to perform CPR.
On Monday, in the AHA journal Circulation, a team headed by the same doctor who led the earlier study issued a statement suggesting that CPR education needs to be targeted to high-risk neighborhoods where residents are more likely to suffer cardiac arrest and have low rates of bystander CPR.
One-size-fits-all training doesn't address the African-American, Hispanic and low-income neighborhoods of any race that most need to have people ready and able to perform hands-only CPR, said Dr. Comilla Sasson, an assistant professor of emergency medicine at the University of Colorado Anschutz Medical Campus in Denver.
Geographic tracking of cardiac arrest -- and where people who are trained live -- can help community leaders target instruction and make a case for residents to prepare.
The Circulation statement also recommended that emergency dispatchers be provided with a standard script to guide willing bystanders through CPR.
A small study conducted by researchers at the University of Pennsylvania and reported at the heart association's 2011 scientific meeting found that most potential bystanders were uncertain of their CPR skills, even though 15 out of 19 people interviewed had been trained at least once.
Once researchers spent a few minutes telling each person a little bit about the new hands-only guidelines, 17 subjects said they felt more confident about their ability to perform CPR using that technique.
The Lucile Packard Children's Hospital in Palo Alto, Calif., sent home CPR-education kits with 117 families as their youngsters were discharged from the hospital. Each kit contained an instructional video and a small mannequin for practice. Most of the parents expressed confidence in their CPR skills up to six months later, a hospital study found.
The heart association offers an even simpler set of instructions for people wishing to learn hands-on CPR: a one-minute introductory video at www.heart.org/cpr.