* Yo estoy bien: This means "I am well" or "I am fine."
* Corazón: This literally means "heart" but it's often used as a term of endearment, similar to "honey" or "sweetheart".
* Y tú cómo estás: This translates to "And how are you?"
Putting it all together, "Yo estoy bien corazón y tú cómo estás" means "I am well, sweetheart, and how are you?"
It's a friendly and affectionate way to ask someone how they are doing.