Each year more than 15,000 women under the age of 55 die of heart disease in the United States. And younger women are twice as likely to die after being hospitalized for a heart attack as are men in the same age group.

Studies show that women tend to wait much longer than men to get emergency care for heart attacks. Once they do go to the ER, their symptoms are often misdiagnosed.

So Judith Lichtman, an epidemiologist at the Yale School of Public Health, tried to figure out why. In a recent study published in Circulation: Cardiovascular Quality and Outcomes, Lichtman and her colleagues conducted in-depth interviews with 30 women, ages 30 to 55, who had been hospitalized after a heart attack.