ATLANTA (AP) -- Only about 1 in 4 Americans know the warning signs of a heart attack and what to do first, according to a new government report.

That's a decline in knowledge since the last survey in 2001, which showed nearly 1 in 3 to be well informed.

The study's lead author, Dr. Jing Fang, called public awareness in the new survey "alarmingly low." Fang is with the Centers for Disease Control and Prevention, which surveyed residents of 13 states and the District of Columbia.

Heart attack warning signs can include one or more of the following five symptoms: shortness of breath; pain or discomfort in the chest; discomfort in the arms or shoulder; a feeling of weakness or lightheadedness; and discomfort in the jaw, neck or back.

Chest pain is the most common symptom. Women are more likely than men to experience some of the other symptoms, particularly shortness of breath and back or jaw pain, according to the American Heart Association.

Anyone experiencing these symptoms should call 911, the heart association advises.

The groups best informed of heart attack warning signs and what to do about them tended to be white, highly educated, and women. Also scoring well were residents of West Virginia, which has some of the nation's highest heart attack death rates.

Each year more than 900,000 Americans suffer a heart attack, and about 157,000 of them are fatal. About half the deaths occur within an hour of symptoms occurring, experts say.

Because different people experience different symptoms, it's important to be aware of all of them, doctors say.

"It's not always massive chest pain," said Wayne Rosamond, a University of North Carolina epidemiology professor and expert on heart disease statistics.

Of course, knowing is not the same as doing: Although most of those who got the heart attack symptoms right said they would call 911, other studies show that only about half of heart attack victims go to a hospital by ambulance, Rosamond noted.

Patients' concerns about lack of health insurance status or other matters may explain why so few go to a hospital, said Rosamond, who was not involved in the new study.

The CDC's findings were based on a random-digit-dial telephone survey of about 72,000 people in 2005.

In West Virginia, more than 35 percent of respondents from that state knew all five warning signs and that they should call 911, compared with 27 percent in the overall study population.

Iowa and Minnesota also were at the top of the list. The gap between West Virginia and the two other states was not statistically significant.

West Virginia consistently ranks among the states with the highest heart attack deaths rates, and also is a leader in smoking, obesity, high cholesterol and other heart disease risk factors. But it's not clear whether personal experience was the reason the state's residents were so well informed. Public health education campaigns or other factors may also explain the result, experts said.

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