Dilated Congestive Cardiomyopathy

Compared with other cardiovascular diseases, heart muscle disease (cardiomyopathy) is relatively rare. In its most common form, the disease accounts for only 50,000 new cases in the United States each year, while the annual number of stroke cases, for example, reaches 500,000. Unlike many other cardiovascular disorders that tend to affect the elderly, cardiomyopathy commonly occurs in the young and can have a tragically brief course. Cardiomyopathy (cardio meaning heart, myopathy meaning muscle disease) refers to a group of disorders that directly damage the muscle of the heart walls. In these disorders, all chambers of the heart are affected. The heart’s function as a pump is disrupted, leading to an inadequate blood flow to organs and tissues of the body. Depending on the nature of the injury or abnormality in the heart muscle and the resulting structural changes in the heart chambers, one of three types of nonischemic (not caused by heart attack) heart muscle disease may be present dilated congestive, hypertrophic, or restrictive. (See Table 15.1.) Massive or multiple heart attacks may also lead to severe heart damage as a result of a disruption of blood supply to heart muscle. The damage can result in functional impairment and structural abnormalities similar to those found in the other types of cardiomyopathy. This type of heart disease, resulting from coronary artery disease, is called ischemic cardiomyopathy. When used alone, however, the term “cardiomyopathy” refers to heart muscle disease that is not caused by heart attacks.