The number of heart
attack cases surged at a Brooklyn, New York, hospital in the two
months after the Sept. 11, 2001 terrorist attacks on the World
Trade Center, suggesting that psychological stress can trigger
serious heart problems, researchers reported at the American
Heart Association’s Scientific Sessions 2003.
In the 60 days after
the terrorist attacks, New York Methodist Hospital in Brooklyn
treated 35 percent more heart attacks and 40 percent more
tachyarrhythmias (irregular heartbeats) than in the 60 days
before the attacks, said Jianwei Feng, M.D., lead author of the
study. Feng is now a cardiology fellow at the University of
Texas Health Science Center in Houston.
Because psychological stress increases stress hormones, people
with heart disease face greater risks of serious cardiac events
during emotional stress, he said. Heart attacks and cardiac
arrhythmias are both related to a surge in stress hormones known
as catecholamines, which stimulate nerve chemicals.
“Anytime a person experiences psychological or emotional stress,
catecholamine levels rise, which increases heart rate and blood
pressure,” he said.
The
risks associated with psychological or emotional trauma have
potentially major implications for people with heart diseases
and risk factors, such as high blood pressure and diabetes.
“Drugs that help control catecholamines, such as beta-blockers,
may reduce the risk in patients with cardiac disease and cardiac
risk factors,” Feng said.
When
the New York terrorist attacks occurred, Feng was a resident at
New York Methodist Hospital, located about four miles from the
World Trade Center’s twin towers. The day after the attacks,
Feng admitted a middle-aged man complaining of chest pain and
shortness of breath.
“The
man told me that he was about a block away from the Twin Towers
when the attack occurred,” Feng said. “Initially, he was OK,
but the more he watched the TV reports about the attack, the
more upset he became. He began to have heart palpitations and
shortness of breath.”
Feng
discussed the patient with cardiology chief C. V. R. Reddy,
M.D., which prompted researchers to study the link between
psychological stress and cardiac events.
Investigators identified 425 patients who had been evaluated at
the Brooklyn hospital for a possible heart attack or heart
rhythm disturbance during the 60 days after the terrorist
attacks. For comparison, they evaluated medical records of 428
patients evaluated for heart attack and cardiac arrhythmias in
the two months before Sept. 11, 2001.
Before the terrorist attack date, 11.2 percent of the patients
had a heart attack. After the terrorist attack date, 15.3
percent had diagnosed heart attacks, a 35 percent increase. The
proportion of patients diagnosed with cardiac arrhythmias
increased from 13.3 percent before the terrorist attack to 18.8
percent afterward – a 40 percent increase.
In
contrast, the proportion of patients with unstable angina (chest
pain) decreased from 47.2 percent before Sept. 11, 2001, to 39.3
percent in the 60 days afterward.
“Our
hypothesis is that the rate of unstable angina was lower because
more patients with unstable angina progressed to acute heart
attacks and acute cardiac arrhythmias,” Feng said.
Researchers examined medical records for patients who received
emergency cardiac evaluations during the same period in 2000.
They found no differences in acute heart attack, cardiac
arrhythmias, or unstable angina.
The
findings have sparked interest in exploring other possible
adverse heart effects related to the psychological trauma of the
terrorist attacks.
Feng
plans to extend the study to patients who have heart pacemakers
or implantable cardioverter-defibrillators (ICD) – implanted
devices delivering electric shocks to the heart to correct
rhythm disturbances.
“A
computer can be used to check an ICD to see how many shocks
occurred before, during and after Sept. 11,” Feng explained.
“We can evaluate ICD activity over a two- or three-month period
to determine the type of shocks and the severity of the
arrhythmias.”
The
findings corroborate those of a study reported at Scientific
Sessions 2002 in which researchers at another New York hospital
reported that the rate of serious heart rhythm disturbances
doubled during the 30 days after the September 11 terrorist
attacks.
Co-authors are Vandana Karri and C.V. R. Reddy.