• Hypertrophic Cardiomyopathy—Child

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


    Hypertrophic cardiomyopathy, or HCM, is a form of cardiomyopathy . This is a condition in which the heart muscle thickens due to genetic problems with the muscle’s structure. As the muscle thickens, it must work harder to pump blood. This strains the heart muscle. Sometimes the thickened muscle gets in the way of the blood leaving the heart and causes a blockage. This blockage can cause a nearby valve to become leaky. HCM can cause uneven muscle growth. This can cause the heart to pump in a disorganized way. Rarely, it can cause abnormal heart rhythms that can be fatal.
    Normal Heart and Heart With Hypertrophic Cardiomyopathy
    Hypertrophic Cardiomyopathy
    Copyright © Nucleus Medical Media, Inc.


    HCM may be caused by a gene that causes an abnormality in the heart muscle. It can be inherited or it can happen from changes in the genes over time.

    Risk Factors

    Having a family member with HCM is a risk factor for your child.


    The doctor will ask about your child’s symptoms and medical history and do a physical exam. Tests may include the following:
    • Stress test —tests how the body responds to exercise, which can help in detecting heart and lung problems
    • Echocardiography —uses sound waves (ultrasound) to examine the size, shape, and motion of the heart
    • Transesophageal echocardiogram —images of the heart are taken using sound waves with a sound wave transducer being put down the throat
    • Heart monitor—a portable electrocardiogram (ECG) records continuous heart activity, usually over a 24-72 hour period, to determine regularity of the heartbeat
    • Heart catheter —a catheter is inserted into an artery in the groin area and threaded to the heart chambers (An x-ray machine shows real-time images of the body as a dye is injected through the catheter. This allows angiograms (photos) to be taken of the blood vessels and the heart.)
    • Chest x-ray —uses radiation to take a picture of structures inside the body
    • Blood tests


    Treatment focuses on controlling symptoms and preventing complications. Talk with the doctor about the best treatment plan for your child. Treatment options include:


    Medicines may be used to help maintain proper and regular heart function. They may also be used to remove excess fluid from the body. If your child has an arrhythmia, he may need anti-arrhythmic drugs. He may also need blood-thinning medicine.


    The thickened portion of the heart muscle is cut and removed. This may be needed if your child has severely blocked blood flow from the heart or if the blockage causes a problem with the other heart valves and structures. If the mitral valve is leaking, surgery may also be done to repair or replace the mitral valve if needed.

    Implantable Cardioverter Defibrillators (ICD)

    This ICD is implanted if your child is at heightened risk for sudden death.


    If a family member has been diagnosed with HCM, your child should be screened for the condition.


    American Heart Association http://www.americanheart.org/

    Cardiomyopathy Association http://www.cardiomyopathy.org/


    Canadian Cardiovascular Society http://www.ccs.ca/

    Heart and Stroke Foundation of Canada http://ww2.heartandstroke.ca/splash/


    American Heart Association. Cardiomyopathy. The American Heart Association website. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4468 . Accessed June 26, 2007.

    Cincinnati Children’s Hospital. Cardiomyopathies. Cincinnati Children’s Hospital website. Available at: http://www.cincinnatichildrens.org/health/heart-encyclopedia/disease/cardiomyopathy.htm . Updated September 2009. Accessed July 5, 2010.

    The Cleveland Clinic Heart and Vascular Institute. Hypertrophic cardiomyopathy. The Cleveland Clinic Heart and Vascular Institute website. Available at: http://my.clevelandclinic.org/heart/disorders/hcm/default.aspx . Accessed June 26, 2007.

    DynaMed Editors. Hypertrophic cardiomyopathy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated October 25, 2010. Accessed November 9, 2010.

    Erwin JP, Nishimura RA, et al. Dual chamber pacing for patients with hypertrophic obstructive cardiomyopathy: a clinical perspective in 2000. Mayo Clin Proc . 2000;75:173-180.

    Maron BJ, Nishimura RA, McKenna WJ, et al. Assessment of permanent dual chamber pacing for patients with hypertrophic cardiomyopathy. Circulation . 1999;99:2927-2933.

    Mayo Clinic. Hypertrophic cardiomyopathy. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/hypertrophic-cardiomyopathy/DS00948 . Updated March 25, 2010. Accessed November 9, 2010.

    McCully RB, Nishimura RA, Tajik AJ, Schaff HV, Danielson GK. Extent of clinical improvement after surgical treatment of hypertrophic obstructive cardiomyopathy. Circulation . 1996;94:467-471.

    St. Luke's Roosevelt Hospital Center. The HCM Program. St. Luke's Roosevelt Hospital Center website. Available at: http://www.hcmny.org/whatis/index.html . Accessed June 26, 2007.

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