Why Are Women More Vulnerable to Broken He

题目：

Why Are Women More Vulnerable to Broken Hearts

0. Women are a lot more likely to suffer a broken heart than men, researchers say. The good news is that it probably won’t kill you.
1. In the first national study of its kind, researchers at the University of Arkansas looked at rates of "broken heart syndrome"—when a sudden shock or prolonged stress causes heart attack-like symptoms or heart failure—and found that it overwhelmingly affects women. Women are at least seven times more likely than men to suffer the syndrome, and older women are at greater risk than younger ones, according to data presented Wednesday at the American Heart Association conference in Orlando.
2. Broken heart syndrome can happen in response to shocking or suddenly emotional events—both positive ones like winning the lottery, or negative ones like a car accident or the unexpected death of a loved one. A flood of stress hormones and adrenaline causes part of the heart to enlarge temporarily and triggers symptoms that can look like heart attack: chest pain, shortness of breath, irregular heart rhythm. The difference is that the factors that would normally cause heart attack, such as a blocked artery, aren’t present. Most sufferers usually recover within a week or two, but in rare cases—about 1%—people die of the condition.
3. Doctors have long known about broken heart syndrome—first described by Japanese researchers two decades ago- and that it seemed to occur mostly in women. So, Dr. Abhishek Deshmukh, a cardiologist at the University of Arkansas who has treated women with broken heart syndrome, became curious about just how gender-specific the condition was. Using a federal database that included data from roughly 1,000 hospitals, Deshmukh found 6,229 cases of broken heart syndrome in 2007. Of those, only 671—just under 11%—were in men. He found that, overall, women had about 7.5 times the risk of broken heart syndrome as men; in people under 55, women were at 9.5 times greater risk than men. Women over 55 were also three times more likely to suffer broken heart syndrome than younger women.
4. Researchers don’t know what causes the gender disparity, but they have some ideas. One theory is that hormones play a role. Another is that men have more adrenalin receptors on cells in their hearts than women do, "so maybe men are able to handle stress better" and the chemical surge it releases. Deshmukh said.
5. About 10% of sufferers will have a second episode at some point, but most return to full heart function without permanent damage or need for follow-up treatment. So, it looks like the way to mend a broken heart is what Mom always said: just give it time.

When encountering a shock or a sudden emotional event, a person’s body releases ______.