The things that make your blood boil may be damaging your heart.
That is the conclusion of a study, published in the August issue of the American Journal of Cardiology, showing that when people with heart disease recount incidents that still make them mad, the pumping efficiency of their hearts drops by 5 percentage points, a significant, though temporary, impairment.
The finding, by researchers at Stanford University, seems to be a missing link in a growing body of evidence showing that hostile people are far more likely to develop severe heart disease, and earlier in life, than their more peaceable peers.
But the study is the first to document a change in heart function brought on by anger; it shows that the heart's pumping efficiency is reduced when people get mad. Although the study is small and much remains to be learned about its findings, experts said it is intriguing and potentially significant.
"A finding like this, that demonstrates a direct effect on heart function from anger, is important," said Dr. Peter Kaufman, acting chief of the Behavioral Medicine Branch at the National Heart, Lung and Blood Institute. "It underscores the role of emotions like anger in the development of heart disease."
The most direct implication of the finding is that patients with coronary artery disease should find ways to handle their anger that will minimize the adverse effects on their hearts, said Dr. Gail Ironson, a psychiatrist who led the research. Dr. Ironson is now at the University of Miami in Coral Gables, Fla.
In the study, Dr. Ironson and her colleagues measured the heart's pumping efficiency in 18 patients with coronary artery disease while they recounted an episode that still made them angry. As the patients recalled the episodes, the pumping efficiency of their hearts decreased an average of five percentage points; seven of the patients had a decline of seven percentage points or greater. Cardiologists regard a decline of that magnitude as evidence of a myocardial ischemia, a drop in blood flow to the heart itself.
In healthy hearts, about two-thirds of the blood is pumped out and a third remains, and under physical or emotional stress the heart pumps more efficiently. But in people with heart disease the amount of blood ejected with each heartbeat decreases, reflecting the weakening of the heart muscle.
"The five-percentage-point reduction we found in the patients' cardiac efficiency during anger is a significant, though mild drop," Dr. Ironson said. "The patients said they were only about half as mad when recounting the episode as they were while it happened. Presumably the pumping efficiency would be even more greatly reduced during an actual angry encounter."
Most of the incidents that the patients in the study were asked to recount were those that they felt were unresolved grievances or injustices done to them.
One man, for example, told of getting angry when he heard a radio report that the United States was giving reparations to Japanese-Americans who had been put in internment camps during World War II. He himself had been a prisoner of war in a Japanese camp.
Another patient was still angered whenever he remembered how, several years before, someone had backed into his car, leading to a frustrating odyssey through insurance company red tape and recalcitrant auto body shops; afterward he got so upset every time he drove his car that he finally sold it in disgust.