Talking about the "Queen of hearts" is common in English, originally from the playing card. See http://en.wikipedia.org/wiki/Queen_of_Hearts. You can see some stories there about characters called 'Queen of hearts', most famously in http://en.wikipedia.org/wiki/Queen_of_Hearts_(Alice%27s_Adventures_in_Wonderland) In the song, there's no obvious particular or real 'queen', it's just a word association. We assume the singer is the 'queen', and she has been 'overthrown' - defeated - in love.