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Hypertrophic Cardiomyopathy—Adult

  • Diana Kohnle
Publication Type:


Hypertrophic Cardiomyopathy—Adult

(Cardiomyopathy, Hypertrophic—Adult; HCM—Adult; Idiopathic Hypertrophic Subaortic Stenosis—Adult; Asymmetric Septal Hypertrophy—Adult; ASH—Adult; HOCM—Adult; Hypertrophic Obstructive Cardiomyopathy—Adult)


Hypertrophic cardiomyopathy (HCM) is a form of cardiomyopathy. The heart muscle thickens more than it should because of problems with the genes. The thick muscle can cause several problems such as:

  • Making it harder for the heart to work and putting strain on the rest of the heart.
  • Interrupting the flow of blood out of the heart.
  • Putting pressure on the nearby mitral heart valve. This can make the valve leaky.
  • Changing the rhythm of the heart. It can make the heart pump in a disorganized way. This can cause abnormal rhythms but is rare.

There are two types of hypertrophic cardiomyopathy:

  • Hypertrophic obstructive cardiomyopathy (HOCM)—the muscle between the two valves of the heart becomes so big that it blocks the blood flow in the heart
  • Nonobstructive hypertrophic cardiomyopathy—the muscle is not large enough to block blood flow.
Normal Heart and Heart With Hypertrophic Cardiomyopathy.

Hypertrophic Cardiomyopathyhttp://services.epnet.com/getimage.aspx?imageiid=81378137Hypertrophic Cardiomyopathy_New.jpgHypertrophic CardiomyopathyNULLjpgHypertrophic CardiomyopathyNULL\\hgfiler1\intellect\images\Hypertrophic Cardiomyopathy_New.jpgNULL130NULL2010-10-11360534Copyright © Nucleus Medical Media, Inc.


Causes of HCM include:

  • A gene that causes the abnormal structure of the heart muscle. It can be passed from a parent to a child or can happen on its own.
  • A problem with a gene that controls the growth of heart muscle
  • Infection

In people at least 60 years of age, HCM is likely to be caused by or related to high blood pressure.

Risk Factors

HCM is usually most severe when it occurs in younger people, but it can happen at any age.

Other things that may raise the risk of HCM include:

  • Having a family member with HCM
  • Being more than 60 years of age and having hypertension


A person with HCM may have:

  • Chest pain
  • Fainting, mainly during exercise
  • Lightheadedness, mainly after exercise
  • Rapid heartbeat
  • Shortness of breath or trouble breathing
  • Fatigue
  • Tiring easily during exercise or activity
  • Shortness of breath when lying down

These symptoms can be caused by some of the side effects of HCM, such as heart arrhythmias. The blocked or reduced blood flow is often the cause of symptoms like lightheadedness, fainting, and difficulty breathing.


The doctor will ask about symptoms and past health. A physical exam will be done.

A blood test may be done to look for changes or possible causes. A different kind of cardiomyopathy can be caused by:

A stress test may also be done to see how the heart works under pressure. Images of the heart may be taken with:

The heart's electrical activity may need to be tracked. This can be done with an ECG that can be worn all day.


The goals of treatment are to manage symptoms and prevent more problems. This may be done with:


Some chronic heart or medical issues raise the risk of HCM. Following the care plan for those health issues plan may help lower the risk of HCM.


Medicines may be used to help the heart work better by:

  • Helping the heart beat
  • Making the blood thinner and reducing the risk of clots


Medicines may be used to help the heart work better by:

  • Helping the heart beat
  • Making the blood thinner and reducing the risk of clots


Surgery may be needed to remove a thickened part of the heart muscle. It may be done if the muscle is blocking too much blood flow from the heart.

Surgery may also be done to repair or replace the mitral valve if it is leaking.

Alcohol Septal Ablation

Alcohol is injected into the blood vessels that feed the enlarged heart. It will make part of the tissue shrink back. This should decrease the blockage in the heart and improve blood flow out of the heart.

Implantable Cardioverter Defibrillators (ICD)

An ICD can help control abnormal heart rhythms. It sends an electrical impulse when the heart needs it. This may be implanted if there is a higher risk for sudden death.





  • Cardiomyopathy in adults. American Heart Association website. Available at: http://www.heart.org/HEARTORG/Conditions/More/Cardiomyopathy/Cardiomyopathy_UCM_444459_SubHomePage.jsp.
  • Explore cardiomyopathy. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health/health-topics/topics/cm.
  • Hypertrophic cardiomyopathy. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hypertrophic-cardiomyopathy.
  • What is HCM? St. Luke's Roosevelt Hospital Center website. Available at: http://www.hcmny.org/whatis/index.html.


  • Michael J. Fucci, DO, FACC
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.