Semantics

У моего отца слабое сердце. My father has a weak heart.
This entry is concerned with the use of the word сердце to refer to human and animal hearts. In some expressions described in this entry, the word сердце refers to the corresponding area on the human chest, e.g. хвататься за сердце "to clutch at one's chest." Common sense will dictate which of the expressions in this entry can or cannot be used to refer to animals.

The word сердце is also used to refer to the heart as the imaginary seat of emotions, e.g. Сердце его наполнилось радостью, "His heart overflowed with joy." This usage is not described in this dictionary.