Age-related changes in the anatomy of the normal human heart.

Recent information has expanded our knowledge regarding age-related changes in the normal heart. With advancing age there are significant increases in heart weight, ventricular septal and probably left ventricular free wall thickness, and in valve circumferences. In the myocardium, there are increases in fat, collagen, elastin, and lipofuscin. The geometry of the heart changes as well, due to decreasing base-to-apex dimension, rightward shift and dilatation of the aortic root, and left atrial dilatation. The aortic and mitral valves thicken and become fibrotic along their appositional surfaces, and their annuli are the sites of collagen degeneration, lipid accumulation, and calcification. The coronary arteries become tortuous, dilated, and focally calcified. There are atrophy and loss of specialized conduction tissue in the atria and ventricles. These changes, while usually modest, might diminish the ability of the aged heart to adapt to the stresses imposed by a number of cardiovascular diseases.