"Zoroastrians traditionally practice sky burials, wherein the deceased’s body is left exposed outdoors — customarily atop a raised, tower-like structure (a dakhma) — so that they can decompose in the open air and allow carrion birds to feed on the body."
It doesn't sit straight up and down, but rather the main mass of the atriums is centered between the lungs, while the ventricles are angled slightly to the left of the sternum. Dextrocardia is when the heart is angled to the right.
This degrading ability to replace dead cells is why the elderly look so... well, the way they do, and why they become more susceptible to disease. However, this can also lead simply to organ failure, which is technically death due to old age.
Built his own cred.