To learn how the bias developed that heart disease is a male condition, we should first examine the technology of how we diagnose heart disease. Historically, the electrocardiogram has created false-positive readings in women. Some women who registered positive on their EKG showed no signs of arterial disease when tested by angiography. This lack of findings underscored the sense that women did not get heart disease. We later realized that false positives stemmed from the fact that adult women often have different EKG responses to exercise. Similarly, QT intervals (one portion of the heart's electrical cycle) prolong in women at adolescence, while remaining roughly equivalent for men. In other words, adult women have a different normal than men.

	EKG of a female patient with a false positive reading in the T-wave.

Testing women using nuclear scans turned out to be similarly flawed. While the radioactive chemicals reliably revealed blood-flow patterns among men, women often had false readings due to shadowing by breast tissue of the heart's emission of radioactive tracers. Also, we have always been reluctant to expose women of childbearing age to radiation. We have since identified other basic gender differences and learned how to use this knowledge to improve the accuracy of all testing procedures. For example, women and men have proportionally different-sized hearts. Women have a lower amount of heart muscle mass per unit area of the body than men. Women may also have differences in their exercise responses, in addition to the differences in their electrical intervals that emerge after puberty. Studies comparing stress echocardiograms to nuclear scans have suggested that ultrasound-based exams may even be superior in managing risk.

Today, we employ ultrasound or echocardiography in women, imaging under the breast tissue and through the rib margins. These approaches allow us to get a direct look at women's hearts, thereby providing more accurate diagnoses. These nonradioactive tests allow physicians to safely test women in their childbearing years. By considering the special diagnostic needs of women, including their specific time of life, physicians can improve the overall quality of care that we deliver to women. When it's appropriate and similarities exist, we should continue to look at the historical data based on men and apply it to women. However, we are increasingly sensitive to the fact that we're charting a new path for women, using more specific tools and knowledge. Interestingly, such research has prompted more creative therapies in men as well—including the application of hormonal therapy and osteoporosis screening.