Leutert G
Z Gesamte Inn Med. 1976 Feb 15;31(4):98-104.
The weight of the heart increases in men and women very rapidly up to the 20th year and after this time grows slowly up to the 90th year. Only after the 90th year there is a decrease of the heart weight. Thickness and length of the heart muscle cells are changing analogous. The capillaries likewise multiply during the first and second decade very quickly and do not diminish in advanced age. We do not find a "withered condition of the top" of the capillary tree and a thickening of the basement membrane. Lipofuscin already appears in heart muscle cells of 7-year-old children; its amount raises continuously. The interstitial connective tissue increases only during the first decade of life. In advanced age a part of the collagenous fibres degenerates. The fibrous framework of the cardiac valves is developing to a solid and stable organ during the first and second decade. After the 50th year the collagenous and elastic fibres show symptoms of degeneration. The different ageing of the blood vessels is demonstrated by the arteries of the iris.