This detailed ultrasound image of a heart was taken by an instrument the size of a laptop computer. Anatomy shows up in black and white. Activity (the direction and speed of blood flow), is in color. Red depicts blood flow toward the ultrasound transducer, and blue represents flow moving away from it.

Two valves, tricuspid (at left in the image) and mitral (right), control blood flow into the next chamber of the heart. In this patient, both are malfunctioning: Blood is flowing from the atria to the ventricles, as it should, but it is also leaking back the other way.