Cardiac enlargemrs to an increase in the size of the heart. There are two types of cardiac enlargement: hypertrophy and dilation. (Though usually occurring separately, they may occur at the same time.) Hypertrophy involves an increase in the thickness of the heart muscle. Dilation involves an increase in the size of the inside cavity of a chamber of the heart. Hypertrophy usually occurs in only one chamber while dilation may occur in one, two, three, or all of the chambers, based on its cause. In most cases, cardiac enlargement is abnormal and accompanied by additional cardiovascular problems. The one exception is regular aerobic exercise, which produces a beneficial enlargement involving both hypertrophy and dilation of the heart. Continue reading →