NEW YORK — Americans who said they became anxious and stressed after the Sept. 11 terrorist attacks — some just from watching the collapse of the twin towers on television — reported higher rates of heart disease up to three years later, researchers said.

While several studies have found high rates of post-traumatic stress disorder and anxiety in first responders or attack survivors, most of the nearly 2,000 people randomly selected nationwide for the study had no direct connection to Sept. 11.

The research showed that before Sept. 11 about 22 percent of the participants reported they had heart ailments. Three years after the attacks, about 31 percent of them said they had developed heart problems.

People who said they were acutely stressed by the attacks were more than twice as likely to have high blood pressure one year after the attacks and more than three times as likely to have heart problems two years after the attacks, according to the study reported in January's issue of the journal Archives of General Psychiatry.

The findings document the physical consequences of stress, especially from watching upsetting events on television, said lead researcher Alison Holman of the University of California-Irvine. About two-thirds of the participants watched the Sept. 11 attacks on live television.

"Seeing something as stressful as that on television is a very important thing to consider," Holman said. "You don't necessarily have to be in the (World Trade Center) towers or in the Pentagon to be at risk for other problems."

The study reported the increased heart disease rates even after taking into account other factors that could cause similar ailments, such as smoking and diabetes.

Steven Woloshin, a physician at the VA Medical Center in White River Junction, Vt., said the findings were problematic because people who report their own medical problems may exaggerate them. He said the study's participants are more likely to develop heart problems as they age.

"I don't think they've proven anything," he said. "There are millions of things that cause heart problems."

Holman and her colleagues used online surveys for their research; the participants were not examined or interviewed beyond the surveys. Most had completed a health survey before the Sept. 11 attacks.

The researchers asked participants whether they experienced anxiety, had flashbacks or worried about terrorism after the Sept. 11 attacks

During follow-up surveys for three years after the attacks, participants were asked whether doctors had diagnosed them, for either the first time or with worsening cases, of high blood pressure, irregular heartbeats and other heart problems.

Psychologist Tom Demaria, who directs a center for bereaved Sept. 11 families at South Nassau Communities Hospital on Long Island, said he helped to counsel a group of about 20,000 people, most of whom didn't live in New York City, in the months after the attacks. They frequently spoke of panic attacks with increased heart rates and tightness in their chests, he said.

"A lot of people reported a lot of phobic reactions. They didn't want to go on bridges, planes. The whole word I kept hearing was ambushed back then," Demaria said.

On the Net:

Archives of General Psychiatry: