Normal changes in the heart include deposits of the "aging pigment," lipofuscin. The heart muscle cells degenerate slightly. The valves inside the heart, which control the direction of blood flow, thicken and become stiffer. A heart murmur caused by valve stiffness is fairly common in older people.
As people age, the heart tends to enlarge slightly, developing thicker walls and slightly larger chambers. The increase in size is mainly due to an increase in the size of individual heart muscle cells.
