Here are some other expressions with the words heart and neck. Translate them into Russian, consulting the dictionary if necessary.

at the heart of smth
to have smth at heart
to set one's heart on smth
with half a heart
to have one's heart in one's mouth
to have one's heart in one's boots
to wear one's heart on one's sleeve
up to the neck
neck of nothing
on the neck
to risk one's neck