"Faint-hearted" turns out to be more than a clichè. Science now supports the stereotype. Hearing of a sudden death in the family, or even walking into a surprise party, can trigger symptoms of a heart attack in some people, according to a new study. But it turns out that most of their heart cells are "stunned," possibly by an onslaught of stress hormones, rather than killed, and they can recover fairly quickly.

What the researchers wanted to know: Can emotional distress really trigger a type of heart attack—or to use medical jargon, left ventricular dysfunction?

What they did: Researchers evaluated 19 patients brought into hospitals affiliated with Johns Hopkins University in Baltimore. These people—all but one of them women—had a median age of 63. They had chest pain and their EKGs showed unusual heartbeats that looked like heart attacks. Their hearts were only pumping, typically, at about 20 of their normal strength. The patients' arteries were also examined for blockages—typical causes of an attack—and for levels of various hormones in their blood. Some patients also underwent biopsies so doctors could look directly at any damage to heart cells.

What they found: Most of the heart cells seemed stunned rather than killed. With these levels of symptoms, doctors say, they expected to see much more cell death, but it was quite limited. Indeed, most patients recovered full heart functions in a matter of days. In addition, examination of the arteries showed they were clear of blockages or lesions normally found in heart attack patients. But the patients did have high levels of stress hormones like epinephrine. All had received shocking news just before their hearts gave out: A husband had died, or a father, or a son. One person was involved in an armed robbery. The news wasn't all bad: One woman had walked into her surprise party.

What this study means to you: In some people, severe emotional stress can do more than set hearts aflutter; it can actually send them into a dangerous pattern of missed beats. It's possible the stress hormones temporarily overwhelm the heart cells, making them function badly. In these cases, however, the heart muscle can recover without the cell death usually seen in a heart attack. So more extreme measures, like surgically implanting a defibrillator, are not warranted. Doctors can tell "broken heart syndrome" from a real heart attack using a battery of standard tests.

Caveats: This was a small study, and the syndrome might be quite rare. Plenty of people get bad news and don't keel over. Nor can the researchers explain why this occurred in 18 women and only 1 man. Finally, the idea that the heart becomes overloaded by stress hormones is still only a hypothesis.

Find out more: For more on the role that emotions may play in heart attacks, read a news report from the American Heart Association.

Read the article: Wittstein, I.S. et al. "Neurohormonal Features of Myocardial Stunning Due to Sudden Emotional Stress." New England Journal of Medicine. Feb. 10,2005, Vol. 352, No. 6, pp. 539–548.

Abstract online: http://content.nejm.org