The heart was always seen as the noblest of the internal organs as well as the most vital. The hearts of martyrs or future candidates for sainthood would be preserved, but never their livers, say, or the entrails - at least not on their own; it was either the heart by itself or the whole lot together.
National Treasure
Ben Gates: A toast? Yeah. To high treason. That's what these men were committing when they signed the Declaration. Had we lost the war, they would have been hanged, beheaded, drawn and quartered, and-Oh! Oh, my personal favorite-and had their entrails cut out and *burned*!
[brief pause]
Ben Gates: So... Here's to the men who did what was considered
wrong, in order to do what they knew was right...
[nodding]
Ben Gates: what they knew was right.