Huns, constipation, blood...confusion

Several part question, stemming from my vague recollection of reading years ago that Attila the Hun died of a heart attack brought on by constipation.

  1. Is it possible for constipation to cause a heart attack? If so, what happens? Do the bowels take up more and more space, eventually preventing the heart from beating?

  2. Is there an authoritative account of how Attila the Hun died? Google turns up some accounts of heart attacks on his wedding night after lots of food and drink, but there are also plenty of references to his getting a bloody nose, being too drunk to notice, and drowning in his own blood.

  3. No reference to Attila’s death from constipation turned up. Am I possibly misremembering this story? Did some other famous person die from a heart attack brought on by constipation?

http://art1.candor.com/barbarian/italy.htm