While women with “big hearts” play well in popular culture, cardiologists see a very different picture – with significant implications for women’s health and medical care. Women have smaller hearts and narrower blood vessels than men and their cardiovascular systems respond to disease and treatment in very different ways. Growing evidence that failure to reflect women’s distinct anatomy in cardiac care leads to deadly disparities in outcomes has recently stimulated development of new diagnostics and increased focus on inclusion of women in medical device trials.