Yet Another Reason to Avoid Stress: Sudden Death
WebMD News Archive
Jan. 17, 2000 (Minneapolis) -- In one of the first studies to show a link
between mental stress and death, researchers at Yale University School of
Medicine have found that stress may actually lead to sudden death. The findings
are particularly important in people with a history of certain irregular heart
rhythms that may already predispose them to sudden death.
Scientists have known for some time that sudden death, usually caused by
heart attacks associated with a lethal heart rhythm, are more prevalent in
populations that suffer earthquake or war. And studies in the laboratory have
shown that the primitive fight-or-flight response to stress alters heart
rhythms in animals, while anger, anxiety, and performance stress alter heart
rates in humans. Now researchers are beginning to learn why.
The patients in the study had a history of a potentially fatal heart rhythm,
and all had been implanted with a cardiac defibrillator. An implantable cardiac
defibrillator is about the size of a pack of cards and is implanted in the
chest. The device is programmed to shock the heart if it detects an abnormal
Researchers performed mental stress tests in the patients. These patients
were grilled with rapid-fire arithmetic questions and harshly reprimanded for
incorrect responses. Patients were then asked to discuss an annoying event, as
the interviewer pressed for further details and asked irritating questions.
The study shows that mental stress not only makes abnormal heart rhythm more
difficult to control, but the same condition is quicker and more difficult to
terminate when patients with irregular heart rhythms are under no sedation.
"In patients with a [rapid heartbeat greater than 100 beats per minute],
mental arousal [can upset the] circuit, creating a potentially more
dangerous [heart rate]," the authors write.
"Patients should be aware that stress really can alter arrhythmias or
make heart rhythms dangerous," Lampert tells WebMD. Through their research,
Lampert says, researchers will be better able to design preventive strategies
in the future.
"This study suggests that treatment of [irregular heart rhythms] should
include integrated medical care, which include not only conventional drug and
device therapy, but also a complementary medicine component focusing on
emotional status and living and working environments," Ruey J. Sung, MD,
tells WebMD. "A mutual understanding of the concept of integrated medical
care between the physician and patient is key to better control [of irregular
heart rhythms]." Sung is director of cardiac electrophysiology and
arrhythmia service at University of California-San Francisco Stanford Health
Care in Stanford, Calif.
Only one woman was enrolled in the study. Whether the effects of mental
stress on arrhythmia differ in women requires further evaluation.