Heart-felt = (of a feeling or its expression) deeply and strongly felt; sincere.
- Please accept my heartfelt apologies/thanks.
- I would like to express my heartfelt gratitude to all the fishermen who volunteered in the rescue operation.
- Louis expressed his heartfelt condolences to the bereaved family.
Hearty = cheerful, spirited, enthusiastic etc( often loudly expressed)
- Louis extended a hearty welcome to the guests.
- A hearty laugh/handshake.
- Hearty congratulations.
(2) (of food) wholesome and substantial.
- We ate a hearty breakfast before we set off.