What does the hand over chest mean?

Heart

In American Sign Language, placing your hand over your heart is the literal sign for “heart.” Use it when talking about your heart, how you feel, and love. Some people also use this sign to mean “home,” like when you finally make it home after a long day. (Just be sure not to mix it up with the sign for “hear,” where your pinky finger is in your ear – you wouldn't want to tell someone you love their ear!)