Cardiac arrest survival improving in U.S. hospitals: study

More people hospitalized for cardiac arrest are surviving compared with a decade ago, according to a U.S. study, possibly because of changes in hospital treatment and the way bystanders respond when somebody collapses.

The study, which appeared in the journal Circulation, found that in 2008, the death rate among U.S. residents hospitalized after cardiac arrest was just under 58 percent - down from almost 70 percent in 2001.

Researchers, led by Alejandro Rabinstein of the Mayo Clinic in Rochester, Minnesota, based their findings on a national hospital discharge database that included nearly 1.2 million people hospitalized for cardiac arrest.

They stressed that the numbers accounted only for cardiac arrest victims who survive long enough to be admitted to the hospital. Many people die before then.

"This does not say anything about the rates of mortality of all (cardiac arrest) resuscitation attempts," Rabinstein said in an email. "But the study does have a clear message. If you have a cardiac arrest and you get to be hospitalized, your chances of surviving the hospitalization are getting better."

Cardiac arrest occurs when a problem in the heart's electrical activity causes it to stop beating normally, making it unable to pump blood to the body. It's fatal within minutes unless the normal rhythm can be restored with a shock from a defibrillator.

But since 2001, a few advances have been made in treating cardiac arrest, Rabinstein's team said.

Sudden cardiac arrest is the sudden, unexpected loss of heart function, breathing and consciousness. Sudden cardiac arrest usually results from an electrical disturbance in your heart that disrupts its pumping action, stopping blood flow to the rest of your body.

Sudden cardiac arrest is different from a heart attack, which occurs when blood flow to a portion of the heart is blocked. However, a heart attack can sometimes trigger an electrical disturbance that leads to sudden cardiac arrest.

Sudden cardiac arrest is a medical emergency. If not treated immediately, it causes sudden cardiac death. With fast, appropriate medical care, survival is possible. Administering cardiopulmonary resuscitation (CPR) - or even just rapid compressions to the chest — can improve the chances of survival until emergency personnel arrive.

One is that experts now recommend bystanders do "hands-only" CPR, which means chest compressions alone and no mouth-to-mouth breathing. It's believed to be easier for laypeople to perform, and may have caused more people to be willing to perform CPR on a stranger.

The public also has more access to devices called automated external defibrillators (AEDs) - portable, layperson-friendly versions of the equipment doctors use to shock an arrested heart.

At hospitals, some things have changed too.