Cardiac arrest is the third-leading killer of Americans, medical experts said Tuesday. Yet most people don't really know what it is, and relatively few research dollars go toward fighting it, according to a report from the Institute of Medicine.

The sudden and complete stoppage of the heart, often without warning, is responsible for an estimated 600,000 deaths a year, surpassed only by all other types of heart disease combined, and all types of cancer.

About two-thirds of cardiac arrests occur outside hospitals; fewer than 6 percent of those patients survive. Even in a hospital, survival rates are just 24 percent.

The authors were surprised to find that the total number of deaths was just an estimate, and probably a conservative one, said Lance Becker, a professor of emergency medicine at the University of Pennsylvania who served on the panel. The committee recommended creation of a national cardiac arrest registry to track cases, the circumstances in which they occur, and survival rates.

Another recommendation - educating the public - was far more specific than a simple awareness campaign. One piece is teaching the difference between heart attack and cardiac arrest, terms often used interchangeably.

A heart attack, caused by restricted blood flow to the heart that damages the heart muscle, causes pain, dizziness, and shortness of breath. Although it requires emergency treatment, the patient in most cases is conscious and able to talk.

Cardiac arrest - sometimes called sudden cardiac arrest or sudden cardiac death - is caused by disturbances in the electrical rhythms that direct the pumping action, causing an immediate shutdown, unconsciousness, and stopped breathing. (A heart attack can lead to cardiac arrest.)

Every minute without the heart pumping decreases the likelihood of survival without disability; death typically comes within 10 minutes.

Among the myths that lead to unnecessary deaths, panelists said, is the belief that one needs a lot of training to help.

"Any CPR and any defibrillation delivered by the public is better than no care at all," committee member Tom P. Aufderheide, an emergency medicine physician at the Medical College of Wisconsin, told reporters at a teleconference. Care from bystanders can more than double chances for survival, he said.

Increasing awareness about cardiac arrest has been Darren Sudman's mission since his 14-week-old son, Simon, died from it in 2005.

The action needed to save a life often is made to seem "much more complex than it needs to be," said Sudman, executive director of Plymouth Meeting-based Simon's Fund. Automatic external defibrillators installed in offices and public places may be marked "for authorized use" even though they are designed for lay people, he said. Mouth-to-mouth has not been considered a necessary part of cardiopulmonary resuscitation for years.

As the American Heart Association notes on its website, "If you see a teen or adult suddenly collapse, call 911 and push hard and fast in the center of the chest to the beat of the classic disco song 'Stayin' Alive.' "

The new report recommends that states make CPR training a requirement for graduation from middle and high school. New Jersey and Delaware both implemented school requirements last year.

Research funding also should be dramatically increased, according to the report. A graphic showed that at least twice as many people die of cardiac arrest compared with stroke, but that the National Institutes of Health funds about 20 times as many studies of stroke as of cardiac arrest.

While the risk factors for stroke, heart attack, cancer, and many other leading causes of death are well known, cardiac arrest often comes without warning.

"There is no test that you can give a person to know that that person is going to have a cardiac arrest in the next year," said Becker. Creating a national registry of cases will determine differences in death rates from community to community, which in turn will help researchers figure out what practices are making a difference, he said.

Becker cited the significant progress made in heart attack survival in recent years and said: "I am hoping that cardiac arrest over the next decade could undergo a similar transformation."

The panel's recommendations cover a lot of ground, including recognition by bystanders, communication with emergency responders, improved technologies, research, and record-keeping, including mapping locations of the automatic external defibrillators that can sometimes help. Overall, the report reflects the fact that it will take a huge scientific and public effort to improve cardiac arrest survival rates.

As one interested questioner put it during the panel's discussion following release of the cardiac arrest report: "How do we make this the Susan B. Komen of heart disease?"