Poetry is a worldwide staple in literature, it can be one of the best ways to express feelings. This is why many poems incorporate the heart, either as symbolism or a concrete object.
Here is one example:
Devotion:
The heart can think of no devotion
Greater than being shore to ocean -
Holding the curve in one position,
Counting an endless repetition.
- by Robert Frost
If you find a poem that relates to the heart in any way, feel free to add it. Or you can even write one of your own.