An Angry Heart Can Lead To Sudden Death
Before flying off the handle
the next time someone cuts you off in traffic, consider the latest
research that links changes brought on by anger or other strong
emotions to future arrhythmias and sudden cardiac arrests, which are
blamed for 400,000 deaths annually.
New research published in the
of the American College of Cardiology finds that
anger-induced electrical changes in the heart can predict future
arrhythmias in patients with implantable cardioverter-defibrillators
While previous studies have
demonstrated an increased incidence of sudden cardiac death during
times of population stress such as earthquake and war, this study
provides the first evidence that changes brought on by anger and other
strong emotions can predict arrhythmias and may link mental stress to
sudden cardiac arrest--which accounts for over 400,000 deaths each
"It's an important study
because we are beginning to understand how anger and other types of
mental stress can trigger potentially lethal ventricular arrhythmias,
especially among patients with structural heart abnormalities," says
Rachel Lampert, M.D., F.A.C.C., associate professor, Yale University
School of Medicine.
Researchers studied 62
patients with ICDs who underwent monitoring during a mental stress
test. Patients who had coronary artery disease or dilated
cardiomyopathy (a condition in which the heart muscle are enlarged) and
a standard indication for ICD were recruited from the Yale
Electrophysiology practice. The mental stress test, conducted in a
laboratory setting shortly after ICD implantation (about 3 months),
asked patients to recall a recent situation in which they were angry or
aggravated. T-wave alternans (TWA), a measure of the heart's electrical
stability, was analyzed during this test. Researchers then followed
patients for a mean of 37 months to determine which had arrhythmias
requiring termination by the ICD.
"We know strong emotion
increases sympathetic arousal," says Dr. Lampert. "In this study, we
found patients with higher levels of anger-induced TWA were more likely
to experience arrhythmias requiring ICD termination."
Patients with ICD-terminated
arrhythmias during follow up (16%) had higher TWA induced by anger
compared with those patients who did not have future arrhythmias. Even
when other clinical factors that predispose patients to higher TWA
levels and/or higher risk of ventricular tachycardia/ventricular
fibrillation were controlled for (e.g., heart failure or history of
arrhythmia), anger-induced TWA remained a significant predictor of
arrhythmias, which led to a heightened risk of up to ten times that of
The development of accurate,
non-invasive risk stratification tests to identify those individuals at
greatest risk for life-threatening arrhythmia is critical. The present
study suggests that mental stress, namely anger, may be yet another
pathway provoking arrhythmias.
"What remains unclear is how
this new T-wave alternans test relates to traditional exercise TWA
testing," according to Dr. Eric J. Rashba, professor of
Medicine, Stony Brook University Medical Center. "It may be that
combining exercise TWA tests with newer mental stress TWA tests may
help clinicians better select patients likely to have arrhythmia and,
in turn, benefit from a defibrillator; however, more study is needed."
In contrast to exercise,
mental stress doesn't elevate one's heart rate much, suggesting that
changes seen with mental stress may be due to a direct effect of
adrenaline on the heart cells. Therefore, mental stress testing could
provide an alternative to atrial pacing for patients unable to
exercise, according to Dr. Lampert.
"More research is needed, but
these data suggest that therapies focused on helping patients deal with
anger and other negative emotions may help reduce arrhythmias and,
therefore, sudden cardiac death in certain patients."
For more information on the
American College of Cardiology, visit www.acc.org.