Nov. 12, 2003 -- The number of heart attacks at a Brooklyn hospital surged by 35% in the two months following the Sept. 11 terrorist attacks on the World Trade Center only a few miles away in Manhattan.
Researchers say the findings suggest that major psychological stress can trigger a cascade of biological events in the body that can lead to serious heart problems, especially in people with risk factors such as high blood pressure or diabetes.
Previous studies have shown that people living in close proximity to the World Trade Center experienced higher stress and stress-related disorders after the terrorist attacks on 9/11 than those who lived further away.
Researchers say that type of psychological trauma stimulates stress hormones in the body, such as catecholamine, that increase the heart rate and blood pressure and can trigger a heart attack in people at risk.
Heart Attacks Surge After Stressful Events
Researcher Jianwei Feng, MD, conducted the study as a resident at New York Methodist Hospital, which is about four miles away from the World Trade Center in a tree-lined residential neighborhood in Brooklyn. He says that the day after the attack, he admitted a middle-aged man complaining of chest pain and shortness of breath.
"The man told me he was about a block away from the Twin Towers when the attack occurred," says Feng in a news release. "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."
That patient got Feng thinking about the link between psychological stress and heart attack and began the study, which was presented this week at the American Heart Association's Scientific Sessions 2003 in Orlando, Fla.
Surge Suggests That Psychological Stress Can Trigger Heart Attacks
Researchers looked at 425 patients who had been evaluated at the hospital for a possible heart attack or heart rhythm disturbance (cardiac arrhythmias) in the 60 days following the Sept. 11 terrorist attacks and compared them with the medical records of 428 patients who were evaluated for similar heart problems in the two months before 9/11.
They found major differences in the severity of heart problems diagnosed in patients admitted before and after the attacks. After 9/11, more than 15% were diagnosed with heart attacks compared with 11.2% before the attacks, a 35% increase. The percentage of patients diagnosed with cardiac arrhythmias also increased by 40% after 9/11, from 13.3% before the attacks to 18.8% afterward.
But the percentage of patients diagnosed with chest pain (unstable angina), a less serious diagnosis, actually dropped from 47.2% before the attacks to 39.3%.
"Our hypothesis is that the rate of unstable angina [chest pain] was lower because more patients with unstable angina progressed to acute heart attacks and acute cardiac arrhythmias," says Feng, who is now a cardiology fellow at the University of Texas Health Science Center in Houston.
Researchers also compared the medical records of patients who were evaluated for heart problems in the hospital's emergency room for the same period in 2000 and found no major differences in diagnoses.
Feng says that with a better understanding of how psychological stress may trigger heart attacks, doctors may be able to intervene during times of stress to help people at risk.
"Drugs that help control catecholamines, such as beta blockers, may reduce the risk in patients with cardiac disease and cardiac risk factors," says Feng.