Originally appeared on the NOVA Web site Cut to the Heart. Sure, you know how to steal hearts, win hearts, and break hearts. But how much do you really know about your heart and how it works?

Heart failure sounds scary - because it is. But here's the thing: millions of Americans are walking around right now with a ...

Sure, you know how to steal hearts, win hearts, and break hearts. But how much do you really know about your heart and how it works? Read on to your heart's content! Put your hand on your heart.