SAN ANTONIO (AP) - The death rate from cardiac arrest rose surprisingly among young American adults in the 1990s, climbing 10 percent in men and 32 percent in women, federal officials said Thursday.

Cardiac arrest is still rare under age 35, accounting for just 1 percent of all deaths from this cause. But experts say the newly recognized increase is troubling and almost certainly represents a real trend and not a statistical blip.

Researchers believe a major reason for the increase is the epidemic of obesity, along with increased smoking and drug abuse, particularly cocaine, which can be a powerful trigger of cardiac arrest.

Doctors from the Centers for Disease Control and Prevention conducted the first-ever survey of cardiac arrest in people ages 15 to 34. They released the figures in San Antonio at an epidemiology conference of the American Heart Association.

Across the United States, the number of fatal cardiac arrests in this age group rose from 2,710 in 1989 to 3,000 in 1996. In all, 23,320 young adults died, almost three-quarters of them men.

``It's a very scary finding, and it deserves a lot of attention,'' said Dr. Murray Mittleman of Beth Israel Deaconess Medical Center in Boston. ``If it is a behavioral factor, such as smoking or illicit drug use, that will be very important to tease out.''

Dr. George Mensah, chief of the CDC's cardiovascular division, said that doctors have traditionally considered cardiac arrest to be exclusively a problem of older people.

``We need to increase awareness,'' he said. ``Dying suddenly is not just an old folks' problem. It can happen to young people, too. Three thousand deaths are not trivial. These are people who should not die suddenly.''

Mensah said researchers were especially disturbed by gender and racial disparities. During the eight years, the death rate from cardiac arrest increased three times faster in women than in men.

It went up 19 percent in blacks and 14 percent in whites. The study did not break down the increase in other racial and ethnic groups.

In 1996, the last year of the survey, the death rate for men ranged from two per 100,000 for those in their late teens to 11 per 100,000 for those in their early 30s. In women, this ranged from one to 4 per 100,000 for the two age groups.

Cardiac arrest occurs when the heart suddenly quits pumping in an organized way, stopping blood circulation. Unless victims are quickly revived by defibrillators, they soon die or suffer irreversible brain damage.

Although the specific triggers in the young are unclear, doctors know that in older people, cardiac arrest often results from the same disease process that makes the arteries clog up.

``Sudden cardiac death is a tragedy in anyone, and it is a particular tragedy in a young person,'' said Dr. Rose Marie Robertson of Vanderbilt University, president of the heart association. ``Clearly we don't understand all the underlying reasons for this increase. It clearly has happened at a time when we've seen an increase in cardiac risk factors.''

According to federal figures, 17 percent of U.S. high school students say they smoke cigarettes regularly, compared with 12 percent a decade ago.

Twelve percent of people in their 20s are now considered obese, compared with 7 percent 10 years ago. Among people in their 30s, obesity has risen from 11 percent to 19 percent.

Too much weight causes an array of ill effects that might increase the risk of cardiac arrest, including higher cholesterol levels, high blood pressure and diabetes.

Copyright 2001 The Associated Press. All rights reserved.