The Greeks held that it controlled reason, thought and emotion.
It's possible that the Greek association with of ivy withe the god Dionysus (the god of sensual things)
let to the heart being identified with romantic love.
And, in time, eternal love.
A symbol of union and love.
Symbolizes an ideograph used to express the idea
of the 'heart' in its metaphorical or symbolic sense
as the center of emotion including:
affection and love, especially romantic love.