We all know that a broken heart hurts, from the stabbing shock of being dumped on Valentine's Day to the deep grief following the loss of a loved one. But there is increasing evidence that shows some people may actually die from heart failure in the wake of extremely emotional events.

British cardiologist Alexander Lyon told the Guardian newspaper yesterday that "broken heart syndrome" could be responsible for about 2 percent of the 300,000 heart attacks that occur every year in the United Kingdom. New research is helping doctors accurately diagnose broken heart syndrome, so that they can learn how common it really is.

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It's thought that a massive surge of adrenaline brings on broken heart syndrome. It can be triggered by both negative and positive events, all the way from grief to winning the lottery. Doctors refer to the syndrome as "stress cardiomyopathy" or "takotsubo cardiomyopathy."

Unlike a typical heart attack, which occurs because a blockage has formed in one of the heart's arteries, preventing blood flow, no blockage occurs in broken heart syndrome. Instead, doctors believe that the adrenaline surge can cause the lower chamber of the heart to go into temporary paralysis, which forces the upper chamber to overwork, causing typical heart attack symptoms.

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"Humans have always been exposed to these kinds of stresses," Lyon told the

Interestingly, doctors diagnose broken heart syndrome much more frequently in women than in men. The theory is that women may be better able to survive the adrenline surge's effects on the heart than men, who might die from the heart failure before the condition can be diagnosed. Patients who survive usually fully recover.

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