March 25, 2002 -- How the heart reacts to mental stress may be the difference between life and death for some people with heart disease. New research shows that mental stress can trigger a potentially deadly slowdown in blood flow to the heart.
The study, published in Circulation: Journal of the American Heart Association, shows that mental stress increased the risk of death by as much as three times for some heart disease patients. Previous studies have already shown that mental stress is linked to heart attack and other problems, but this is the first study to show that it can increase the risk of death as well.
Researchers used a type of imaging test that allowed them to see abnormalities in the motion of the heart's walls while it was pumping and suffering from insufficient blood supply -- a condition known as ischemia.
"Wall-motion abnormalities are specific markers of ischemia," says study author David S. Sheps, MD, associate chief of the division of cardiovascular medicine at the University of Florida Health Sciences Center, in a news release. "Normally, there is a nice symmetrical motion of the heart. With ischemia, certain portions [of the wall of the heart] will contract less vigorously or bulge out."
Researchers say mental stress increases the body's demand for oxygen by raising blood pressure and heart rate. For people who already suffer from heart problems, the added burden of mental stress may increase their risk of death.
The researchers saw wall-motion abnormalities during a test that simulates mental stress in 20% of patients with heart problems. And patients with heart problems had nearly three times the death rate from any cause as did those without them. Other tests, including the standard treadmill exercise stress test, or looking at other known risk factors, did not distinguish those who died from those who lived.
Women and people with a history of diabetes were more likely to have wall-motion abnormalities, but all 17 people who died during the five-year follow-up period were men.
"This suggests that mental-stress testing may provide additional ... information beyond that given by a standard exercise test," write the authors.
Sheps says more research is needed to find an inexpensive way to make mental-stress testing more practical for routine use.
"It is important to find out which patients are at risk and to learn ways to tailor treatment to those at risk. It may be that we can alter the lifestyles of people at risk and get them to respond differently to the stress," says Sheps.-->