http://www.scientificamerican.com/article.cfm?id=what-causes-chest-pains
... terms such as “heartache” and “gut wrenching” are more than mere metaphors: they describe the experience of both physical and emotional pain. When we feel heartache, for example, we are experiencing a blend of emotional stress and the stress-induced sensations in our chest...
http://en.wikipedia.org/wiki/Love_sickness