The afflicted character can have any number of problems for which heart disease provides a suitable emblem: bad love, loneliness, cruelty, pederasty, disloyalty, cowardice, lack of determination. Socially, it may stand for these matters on a larger scale, or for something seriously amiss at the heart of things.
The physical disease again reflects the mental disease---the character has heart disease, and the author's heart hurts (but not in the physical sense). I like that a lot. I also see that there's a pun at the end lol.
