Alternate Names: Cardiomyopathy - idiopathic
Causes and Risks:
Cardiomyopathy has many causes, including nutritional deficiencies, deposits in the heart muscle associated with medical conditions, anemia, stress, viral infections (rare), alcoholism, coronary artery disease, and others.
Idiopathic cardiomyopathy refers to a weakening of the heart muscle, a "cardiomyopathy" for which there is no identifiable cause. A certain percentage of cases with an unidentified cause can be the end result of a viral infection of the heart muscle called myocarditis. It is still not well understood as to why some people with myocarditis recover their heart muscle function spontaneously, and others progress to heart failure.
Risk factors include obesity, personal or family history of cardiac disorders such as myocarditis, use of certain medications, smoking, and alcoholism. Cardiomyopathy also occurs when there is damage to the heart, resulting in scarring (fibrosis) or deposits in the tissues of the heart muscle.
Symptoms often develop gradually and usually include symptoms of right heart failure and/or left heart failure.
Prevention:
Modify risk factors that can be controlled. Eat a generally well-balanced, nutritious diet, exercise to improve cardiovascular fitness, and avoid or minimize smoking and consumption of alcohol.
Symptoms:
Signs and Tests:
Cardiomyopathy is usually diagnosed when it is discovered as the cause of heart failure.
A physical examination may reveal an irregular or a rapid heartbeat. There may be distended neck veins, enlarged liver, dependent edema, and signs of pleural effusion (fluid around the lungs). Listening to the chest with a stethoscope may reveal lung crackles or abnormal heart sounds. Blood pressure may be low or may drop upon rising (orthostatic hypotension).
An ECG may show arrhythmias or other abnormalities.
Heart enlargement, congestion of the lungs, decreased movement/functioning of the heart, decreased cardiac output, or heart failure may show on:
A heart biopsy may be helpful to rule out other causes of cardiomyopathy.
Laboratory tests vary depending on the suspected cause.
Cardiomyopathy is classified as idiopathic when all known possible causes have been ruled out.
Treatment:
Hospitalization may be required when symptoms are severe. Treatment is focused on relief of symptoms. It is essentially the same as the treatment of heart failure.
Medications may include diuretics, ace-inhibitors, digitalis, and other medications.
A low-salt diet may be recommended. Fluid may be restricted in some cases.
A heart transplant may be considered if heart function is very poor.
Daily weights may be recommended. A weight gain of 3 or 4 pounds or more over 1 or 2 days may indicate fluid accumulation. Activity may be restricted as symptoms progress. Advice to stop smoking and stop drinking alcohol may be given, because these habits may make the symptoms worse.
Prognosis: The outcome varies. There is no known cure for idiopathic cardiomyopathy. Some affected individuals remain stable for long periods, some deteriorate gradually, and some deteriorate rapidly.
Complications:
Call your health care provider if symptoms indicate cardiomyopathy may be present.
Call your health care provider or go to the emergency room (if necessary) if chest pain, palpitations, faintness or other new or unexplained symptoms develop.
