I don't know if the Wraith have hearts or not. A good beheading ought to cover it, though. Even if the Wraith doesn't die, the body can't see where it's going without a head, and the head can't go anywhere without a body.

You're still reading Anita Blake? I admire your fortitude. I quit after Obsidian Butterfly. I so totally miss the days when she actually was a vampire hunter.