Cardiomyopathy

What Is It?

Cardiomyopathy refers to changes in the heart muscle that prevent part or all of the heart from contracting normally. Doctors further divide cardiomyopathies into three types, based on the physical changes that occur in the heart:

• Dilated cardiomyopathy — In this form of cardiomyopathy, the damaged heart muscle stretches out of shape. The heart becomes enlarged and loses its ability to pump blood effectively, ultimately leading to heart failure. The most common heart diseases that lead to a dilated cardiomyopathy are coronary artery disease, prolonged untreated high blood pressure, and alcohol use. Other diseases that result in cardiomyopathy include myocarditis (heart-muscle inflammation, often starting as a viral infection or after a women gives birth), untreated thyroid disorders, radiation and chemotherapy treatments, inherited genetic diseases, and disorders in which the heart muscle is overloaded with iron or a protein called amyloid.
• Hypertrophic cardiomyopathy — In this form of cardiomyopathy, there is an abnormal thickening of the muscular heart wall, which does not allow the heart muscle to relax during the filling phase. In certain types of hypertrophic cardiomyopathy, the muscle can become so thickened that it can lead to obstruction of blood flow out of the heart.
• Restrictive cardiomyopathy — In this form of cardiomyopathy, the heart's muscular walls become so rigid that the heart cannot fill properly.

Symptoms

The symptoms of cardiomyopathy vary, depending on the physical changes they cause in the heart:

• Dilated cardiomyopathy — Symptoms can include shortness of breath, especially with exertion; fatigue; difficulty breathing while lying down, especially at night during sleep; leg swelling; palpitations; and chest pain.
• Hypertrophic cardiomyopathy — Symptoms, when they occur, are usually the same as the symptoms of dilated cardiomyopathy. In idiopathic hypertrophic cardiomyopathy without obstruction, the first symptom may be fainting or even sudden death. Chest pain also can occur, usually with exercise.
• Restrictive cardiomyopathy — The predominant symptoms are related to edema, with fluid accumulation in the legs and abdomen (called ascites). Shortness of breath, especially with exertion, also occurs.

Diagnosis

Your doctor will review your medical history. He or she also will ask about your family's history of heart disease, and about any family members whose death was sudden and unexplained. Your doctor will want to know more about specific circumstances that trigger your heart-related symptoms (chest pain, shortness of breath, palpitations, leg swelling).