At autopsy, the heart of a 70-year-old man weighs only 300 g and has small right and left ventricles. The myocardium is firm, with a dark chocolate-brown colour throughout. The coronary arteries show minimal atherosclerotic changes. An excessive amount of which of the following substances would most likely be found in the myocardial fibers of this heart?
Ans :B Hemosiderin
Lipofuscin is a “wear-and-tear” pigment that increases with aging, particularly in liver and myocardium.
The pigment has minimal effect on cellular function in most cases. Rarely, there is marked lipofuscin deposition in a small heart, a so-called brown atrophy.
Melanin pigment is responsible for skin tone: the more melanin, the darker the skin.
Hemosiderin is the breakdown product of hemoglobin that contains the iron.
Hearts with excessive iron deposition tend to be large.
Glycogen is increased in some inherited enzyme disorders, and when the heart is involved, heart size increases.
Bilirubin, another breakdown product of hemoglobin, imparts a yellow appearance (icterus) to tissues.