A new study has found that chest compressions are at least as effective at saving patients after cardiac arrest as immediate electrical defibrillation.

In the United States, only about eight percent of cardiac patients who sustain heart attack outside the hospital survive.

But a study of the two well-known strategies for getting the heart going again and thus increasing the chance of survival, found that chest compressions are as effective, if not more so, than using a defibrillator's electric shock to restore normal heart rhythms.  Defibrillation is considered the standard method of resuscitation in cardiac arrest.

Pascal Meier, an interventional cardiologist at the University of Michigan Health System, led an international study of 1,500 patients, comparing survival rates among those who had received compressions from emergency medical personal for 90 seconds prior to defibrillation.

"What we wanted to test is whether it would be better to start first with good quality chest compressions to prepare the heart for this electrical shock to get some blood circulation to the brain and heart before we apply the shock," Meier said.

Researchers found there was no difference in survival among cardiac patients when emergency personnel followed the current guidelines, administering defibrillation as soon as possible.

While an analysis of data from four studies found no difference in short term survival, there was a slight edge in long term survival one year after cardiac arrest among those who received chest compressions prior to defibrillation, especially if emergency medical personnel are delayed getting to the scene. "For people with longer-duration cardiac arrest, it really helps to start these good quality chest compressions," Meier said.

Meier says that means bystanders should start administering compressions immediately if emergency medical help has not yet arrived.

But he says many people don't know what to do and are afraid of hurting the person experiencing cardiac arrest.

Meier says good quality chest compressions are done in the middle of the chest. "On the breast bone, usually about two fingers above the lower end of the chest bone you put both hands and then you really have to straighten your arms and do really strong compressions there."

An article comparing chest compressions with defibrillation in cardiac arrest is published in the on line journal BMC Medicine.