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Hypertrophic Cardiomyopathy

What is hypertrophic cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) a problem with the heart muscle that can make it harder for the heart to pump well. It can cause heart failure.

How does it occur?

HCM is usually caused by a defect in the genes that control the growth of the heart muscle. The defect causes the cells to become tangled and jumbled up instead of having their normal pattern. The walls of the heart become thick and stiff. The thickening may make it harder for the heart to pump well. The changes may happen throughout the heart or in just a small part of it.

Because it can be caused by a defect in genes, HCM often runs in families.

Sometimes HCM occurs because of high blood pressure. Having very high blood pressure for a long time can make the walls of the heart thicken. The thickening may get severe enough to cause HCM.

People of all ages may have HCM, but younger people are likely to have a more severe form of the disease. Young athletes who die during heavy exercise are often found to have HCM.

What are the symptoms?

HCM varies widely in how it affects people. Many people have no symptoms at all. Others may be nearly disabled.

The most common symptoms are:

  • chest pain
  • shortness of breath when you are physically active

Other possible symptoms are:

  • dizziness, particularly when you stand suddenly
  • fainting.

How is it diagnosed?

Your healthcare provider will ask about your symptoms, examine you, and listen to your heart. You may have:

  • chest X-rays
  • electrocardiogram (ECG), which is a recording of your heart's electrical activity
  • echocardiogram (an ultrasound scan of the heart), which can show areas of heart muscle that are thick.

You may also need to wear a Holter monitor. A Holter monitor is used to record your heart rhythm for at least 24 hours.

Because the disease may run in families, your healthcare provider may suggest testing other members of your family.

How is it treated?

If tests show no blockage to blood flow and no potentially dangerous heart rhythm problems, regular checkups by your healthcare provider may be all you need.

If you are having symptoms, you may need treatment. There is no treatment for the gene defect causing HCM. Your healthcare provider can only treat the effects of the genetic defect.

If your heart's ability to pump is getting worse, you could have heart failure. Most heart failure in people with HCM results from abnormal heart muscle contraction or blocked blood flow. Medicines such as beta blockers and calcium channel blockers may be used to relax the heart muscle and reduce the amount of blockage.

Procedures that may be used to treat HCM include:

  • removal of a piece of heart muscle (a procedure called myectomy) with a heart catheter or surgery
  • insertion of an artificial pacemaker or an implantable cardioverter-defibrillator (ICD) to treat abnormal heart rhythms
  • surgery to repair a valve damaged by HCM.

How long will the effects last?

Most people with mild forms of HCM have very few problems and a normal life expectancy. Some people with HCM develop heart failure. Very rarely, people with HCM die suddenly.

If you have HCM, your main risk is that you may start having abnormal heart rhythms. In some cases this abnormal heart rhythm may be a type called ventricular fibrillation. Ventricular fibrillation prevents coordinated beating of the heart muscle. As a result, blood circulation can come to a sudden stop. Emergency treatment with an electrical shock is then needed to prevent death.

How can I help take care of myself?

  • Take your medicines regularly, carefully following your healthcare provider’s instructions.
  • Weigh yourself regularly and let your provider know if you suddenly gain weight.
  • Ask your provider how much you can exercise and try to remain active. For some types of cardiomyopathy certain sports or activities are not recommended. You should ask your provider about activities such as scuba diving or competitive sports.
  • Ask your provider how much fluid you should drink every day. You may need to make sure that you don’t get dehydrated because it puts more stress on the heart and can worsen your symptoms.
  • Make changes in your diet if recommended by your provider.
  • Call your provider if you have changes such as shortness of breath, lightheadedness, or chest pain.
  • If you have severe HCM, you may wish to wear a medical alert bracelet in case of an emergency.
  • Call your provider if you have changes such as shortness of breath, lightheadedness, or chest pain.
Written by Donald L. Warkentin, MD.
Published by RelayHealth.
Last modified: 2011-06-01
Last reviewed: 2011-03-16
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2011 RelayHealth and/or its affiliates. All rights reserved.
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