MONDAY, March 22, 2004 (HealthDayNews) -- The emotional stress encountered in everyday life can trigger abnormal heart rhythms in vulnerable people, a new study finds.
"This is the first study to demonstrate that mental stress alone can induce specific heartbeat irregularities that identify patients with high vulnerability to arrhythmias," says Willem Kop, an assistant professor of psychology at the U.S. Uniformed Services University of Health Sciences.
Kop is lead author of a report on the study that appears in the March 23 issue of Circulation.
It has long been known that physical stress can precipitate arrhythmias, which are wildly abnormal heartbeats that can sometimes be fatal. Putting high-risk patients through "the mental equivalent of an exercise stress test" shows that emotional stress can have the same effect, he says.
The test group included 17 people whose heart malfunction was serious enough to require implanted defibrillators, which are devices that give an electric jolt to restore normal heart rhythm when it goes awry. They and 17 people with healthy hearts underwent both exercise and mental stress testing.
The mental tests included having the participants recall recent incidents that angered them, and the bothersome task of subtracting multiples of the number 7 from a four-digit number while they were interrupted from time to time without warning and pestered to improve their performance.
The heartbeat irregularities showed up much faster in the defibrillator users during the mental-stress tests than during the physical-stress tests, Kop says. It took an increase of 53.3 beats per minute during exercise to cause irregularities. But those irregularities were triggered after an increase of just 9.7 beats per minute during part of the mental stress testing, he says.
"Now we need to show two things -- whether we can predict future events, and are there subgroups of patients at particularly high risk of developing arrhythmias, such as those with Type A personailities," Kop says.
One group clearly at higher risk consists of "people who do not exercise much any more," a growing percentage of the American population, he says.
The study wasn't designed to offer advice on ways to lessen the health risks for people who are prone to stress in daily situations. But they could try some well-established stress management techniques, Kop says.
One thing not to do is have a drink to steady the nerves, says Dr. J. Michael Gaziano, an associate professor of medicine at Harvard Medical School. He's also a member of a research group reporting that moderate drinking of alcohol can reduce the risk of death from cardiovascular disease in men with high blood pressure.
The alcohol study was done because some experts advise people with high blood pressure to avoid alcohol entirely, Gaziano says. "They know that drinking a lot can raise blood pressure, so they extrapolate to if you have high blood pressure, don't drink at all," he says.
But the report on men enrolled in the Physicians' Health Study, reported in the March 22 issue of the Archives of Internal Medicine, finds those with high blood pressure who averaged a drink a day had a 44 percent lower death rate from cardiovascular disease than nondrinkers, while those who had at least one drink a week had a 39 percent lower risk.
That finding doesn't apply to stressful situations because alcohol reduces the risk not by its effect on heart rhythm but because it has a beneficial effect on blood cholesterol levels, Gaziano says.
And he adds the definition of "moderate" drinking is flexible, and is notably different for men and women.
"The best thing a person with high blood pressure can do is to talk over his or her drinking habits with a doctor," Gaziano says.
More information
The American Heart Association describes the role of stress in heart disease and what can be done about it. For more on stress, visit the American Psychological Association.
