Level of Mental Stress May Help Doctors Predict Heart Attack
Dec. 8, 1999 (Atlanta) -- "Calm down before you give yourself a heart
attack!" Everyone's heard or thought something like that at some point in
their lives. And for people with heart conditions, it's good advice. But how to
effectively calm down is another thing entirely. That question might soon
receive more research, thanks to the results of a new study.
Physical response to mental stress helps predict health outcomes for
patients with coronary artery disease (CAD), according to a group of
researchers whose work is published in the Dec. 1 issue of The American
Journal of Cardiology. Ischemia, or lack of blood flow to the heart by
blockages in the arteries, is a common cause of heart disease. Thus, a new
direction for therapy may involve blocking the ability of mental stress to
cause the heart to work harder in heart patients.
"Behavioral triggers are important in cardiovascular disease,"
senior author John S. Gottdiener, MD, tells WebMD. "Not only do they
account for most of the episodes for cardiac ischemia, but they have importance
for indicating the outcome for coronary artery disease ... While an exercise
event is more potent [for showing blocked blood flow to the heart], most people
don't have 20 to 30 episodes during the day where they're performing vigorous
exercises. ... However, people are constantly mentally and emotionally engaged.
... So, the extent that those type of mental or emotional activities are able
to affect the way blood flow goes to the heart in patients with coronary
disease ... [has] become extremely important."
Gottdiener, who was a professor of medicine at Georgetown University Medical
Center in Washington while participating in the study, says about half of the
people who have restricted blood flow while exercising also will have
restricted blood flow brought on by mental stress. Therefore, those heart
patients who show signs of restricted blood flow from mental stress are at a
greater risk of heart failure than are those who show the restricted flow on
standard exercise tests.
The 79 patients included in this follow-up study had participated in two
previous studies examining the effect of mental stress-induced ischemia on
those with coronary artery disease. Tests were performed on these patients
using either ultrasound or radionucleotide ventriculography (RNV), a procedure
where radiated dye is injected into the person to help show areas where blood
flow is restricted. These measurements, as well as heart rate and peak changes
in blood pressure, were taken at rest, during mental stress, and during
exercise. Mental stress was induced by public speaking and mental arithmetic
tasks. New or worsened heart abnormalities were detected in 77% of patients
during exercise testing and 57% during mental stress. Nearly all patients who
experienced restricted blood flow during mental stress also experienced it