Does this sound familiar? You're rushing to catch a plane, and suddenly, a wave of seething pain stretches across your chest. It may be fleeting or long-acting. You may have previously experienced this kind of discomfort while at rest. But here's the kicker: On examination, your coronary arteries show no signs of blockage.

Doctors used to brush off these reports of chest pain in women, suggesting that it was all in their head. When stress tests detected abnormalities, the findings were considered false positives. The condition was dubbed "cardiac syndrome X," and it was believed to be benign.

"[This type of chest pain in women has] been sort of dismissed for many, many years because we did not study women," says C. Noel Bairey Merz, MD, director of the Preventive and Rehabilitative Cardiac Center at Cedars-Sinai Medical Center in Los Angeles.

But recent research into women's heart health has revealed that these reported bouts of angina are very real. Thanks to the Women's Ischemia Syndrome Evaluation (WISE) study, a long-term multicenter investigation sponsored by the National Heart, Lung, and Blood Institute, a clearer picture of this mysterious condition is beginning to emerge.

The latest WISE study findings make it clear that among women with chest pain and no evidence of blocked coronary arteries, there is often a high prevalence of microvascular dysfunction, a condition in which the tiny blood vessels that nourish the heart either don't dilate sufficiently or constrict inappropriately. When that happens, the heart is starved of blood and oxygen, causing chest pain.

In addition, these women with chest pain often experience a diffuse sort of plaque accumulation not readily detected by a traditional angiogram.