Cardiomyopathy

What Is It?

Cardiomyopathy refers to changes in the heart muscle that prevent part or all of the heart from contracting normally. There are three types of cardiomyopathy, 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. This eventually leads to heart failure. The most common heart diseases that lead to a dilated cardiomyopathy are coronary artery disease, and prolonged untreated high blood pressure. Excessive alcohol use over a long time also can lead to dilated cardiomyopathy. Other diseases that can cause cardiomyopathy include myocarditis (heart muscle inflammation, often starting as a viral infection or after a women gives birth), untreated thyroid disorders, inherited genetic diseases, and disorders in which the heart muscle is overloaded with iron or a protein called amyloid. Radiation and chemotherapy treatments also can cause this condition.
• Hypertrophic cardiomyopathy In this form of cardiomyopathy, the muscular heart wall thickens abnormally, and the heart muscle cannot relax normally during the filling phase. In certain types of hypertrophic cardiomyopathy, the muscle can become so thickened that it can stop the flow of blood 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 during 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. The condition also can cause chest pain, usually during exercise.
• Restrictive cardiomyopathy The predominant symptoms are related to edema, with fluid accumulation in the legs and abdomen (called ascites). This condition also can cause shortness of breath, especially during exertion.

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.

Your doctor will examine you, paying special attention to your heart. This will be followed by an electrocardiogram (EKG), chest X-ray, blood tests, and an echocardiogram. You may also need other tests, including cardiac catheterization, radionuclide studies, or endomyocardial biopsy, in which a sample of heart muscle is removed and examined in a laboratory.

Expected Duration

Dilated cardiomyopathy sometimes can be reversed when it is caused by overuse of alcohol, poor heart circulation that can be treated (such as with angioplasty or bypass surgery), or myocarditis. Most cases of hypertrophic and restrictive cardiomyopathy are persistent and can get worse over time.

Prevention

The best way to prevent cardiomyopathy is to prevent the diseases that most often cause cardiomyopathy. Know your risk factors for coronary artery disease and modify those risks early in life. Keep blood pressure normal by eating a diet rich in vegetables and fruits, and taking medication regularly when needed. Drink no more than two alcoholic beverages per day and none if you are at high risk of dilated cardiomyopathy. Family members of people with inherited forms of cardiomyopathy should be evaluated by their physicians.

Treatment

The treatment of cardiomyopathy depends on its cause. Here are some of the more commonly advised treatments:

• Medications that prolong life in people with dilated cardiomyopathy angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, beta-blockers, spironolactone (Aldactone)
• Drugs that improve the symptoms of heart failure in dilated cardiomyopathy, including diuretics, ACE inhibitors, angiotensin receptor blockers, and digoxin (several brand names)
• Drugs that help to relax the heart muscle in hypertrophic cardiomyopathy, including beta-blockers and verapamil (several brand names)
• Antiarrhythmic drugs to correct abnormal heart rhythms
• A pacemaker or an implantable defibrillator to prevent fatal arrhythmias

A heart transplant may be necessary for patients whose poor heart function has become totally disabling or life threatening.

When To Call A Professional

Call your doctor whenever you have any of the following symptoms:

• Shortness of breath, with or without exertion
• Difficulty breathing when you sleep or lie down
• Fainting or light-headed spells
• Palpitations
• Leg swelling

Call your doctor immediately if you have chest pain, even if you think that you are too young to be having heart problems.

Prognosis

The outlook varies, depending on the specific cause and severity of the cardiomyopathy. The survival rate of people with most types has improved dramatically in the past 10 years because of the increased number of treatments available.

Additional Info

American Heart Association (AHA)

7272 Greenville Ave.

Dallas, TX 75231

Toll-Free: (800) 242-8721

http://www.americanheart.org/

National Heart, Lung, and Blood Institute (NHLBI)

P.O. Box 30105

Bethesda, MD 20824-0105

Phone: (301) 592-8573

TTY: (240) 629-3255

Fax: (301) 592-8563

E-Mail: nhlbiinfo@rover.nhlbi.nih.gov

http://www.nhlbi.nih.gov/

American College of Cardiology

Heart House

9111 Old Georgetown Road

Bethesda, MD 20814-1699

Phone: (301) 897-5400

Toll-Free: (800) 253-4636, ext. 694

Fax: (301) 897-9745

E-Mail: resource@acc.org

http://www.acc.org/