Much evidence suggests that myocyte enlargement and the consequent thickening of the heart walls are ways that the heart adjusts to increased loads, especially from the growing stiffness of the arteries. Extra loads may also be imposed by disease. One reason cardiovascular researchers are so intrigued by myocyte enlargement is because of its possible links to disease. While enlargement seems to occur in response to aging and stiffening arteries, it is exaggerated by disease, such as coronary artery disease and high blood pressure. While myocyte enlargement seems to be one way the heart adapts to increased loads, there is also evidence that at the oldest ages, it no longer adapts as much.
Older animals have less enlargement in response to heart overloads than younger animals.
In fact, according to one school of thought, heart failure rises with age for the same reason. That is, the reason older people have a higher risk of heart failure is not just because their hearts have had longer to deteriorate. It is because of specific, age-associated changes in healthy hearts and blood vessels that hinder the heart's ability to adapt to disease states. In this view, normal age-associated changes are risk factors for heart disease in older persons. Selected Readings Froehlich JP, Lakatta EG, Beard E, Spurgeon HA, Weisfeldt ML, and Gerstenblith G. Studies of sarcoplasmic reticulum function and contraction duration in young adult and aged rat myocardium.