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What Is Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (also known as HCM, IHSS, hypertrophic obstructive cardiomyopathy) is an illness affecting the heart muscle. It interferes with the heart’s ability to pump blood. Sometimes it also changes the heart’s natural rhythm, which leads to irregular heartbeats (arrhythmias).

One type of cardiomyopathy, hypertrophic cardiomyopathy, occurs when the heart’s muscle fibers grow abnormally. Heart walls thicken, especially in the left ventricle (the main pumping chamber). The left ventricle becomes smaller inside, the heart cannot rest completely between beats, and the ventricle pumps less blood out of the heart. People are at risk for fainting (syncope), chest pain (angina), difficulty breathing (dyspnea), and sudden death.

Hypertrophic cardiomyopathy affects people of all ages, including children. It can cause sudden death even in children and young adults.

What Causes Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy is usually inherited (passed on from parents). Once someone is diagnosed, all immediate family members should be tested. The cause in some elderly people may also involve long-standing untreated high blood pressure (hypertension).

What Are the Symptoms of Hypertrophic Cardiomyopathy?

Symptoms include shortness of breath when walking, performing household tasks, or with any exertion; chest pain; fainting after exercising; and irregular or very rapid heartbeat. Some people have no symptoms, and sudden cardiac arrest may often be the first sign of this disorder.

How Is Hypertrophic Cardiomyopathy Diagnosed?

The health care provider will check the medical history and do a physical examination. Tests for diagnosis include chest x-rays, electrocardiogram (ECG), and echocardiography (ultrasound of the heart). Other tests, such as 24-hour recording of the heartbeat and blood tests may also be done. Genetic testing using a blood test and magnetic resonance imaging (MRI) of the heart may also be done.

How Is Hypertrophic Cardiomyopathy Treated?

Treatment is aimed at controlling symptoms and slowing the disease progress by reducing excessive contractions of the ventricle. Symptoms of heart failure and arrhythmias are also treated. Drugs are usually prescribed to regulate the heart rate and strength of contractions. These drugs include beta-blockers (e.g., propranolol) and calcium channel blockers (e.g., verapamil). A pacemaker/defibrillator/cardioverter is an option to control the heartbeat. It is a small device that is put into the body during surgery. Surgery may also be done to remove part of the abnormal muscle (septal myectomy) and reduce the blockage of blood flow. Destruction of a portion of the wall between ventricles (alcohol septal ablation) may also be done. Heart transplantation is possible for people who don’t respond to other treatments.

DOs and DON’Ts in Managing Hypertrophic Cardiomyopathy:

  • DO take medicine as prescribed by your health care provider.
  • DO tell your health care provider if your symptoms get worse or don’t improve with treatment.
  • DO remember that family members should be checked for this disorder.
  • DO call your health care provider if you have new or worsening chest pain, shortness of breath, swelling in the legs, or fainting.
  • DON’T change your exercise program without telling your health care provider first.
  • DON’T take over-the-counter drugs, foods, or herbal supplements before checking with your health care provider because they may react with your heart medicine.
  • DON’T smoke.
  • DON’T drink alcohol.
  • DON’T use diuretics (water pills).

Contact the following sources:

  • American Heart Association
    Tel: (800) 242-8721
  • American College of Cardiology
    Tel: (800) 253-4636

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc.

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