ServicesCardiovascularConditions We TreatHypertrophic Cardiomyopathy
  • About Hypertrophic Cardiomyopathy


    Hypertrophic cardiomyopathy (HCM) is a complex cardiac disease marked by a thickening of the heart muscle (myocardium). This thickening makes it difficult for the heart to pump blood, forcing it to work harder to get blood throughout the body. HCM also causes disruptions in heart rhythm, which can sometimes be fatal.

    Hypertrophic cardiomyopathy is often asymmetrical, meaning that one part of the heart is thicker than other parts. HCM is usually passed down through families (inherited), and is believed to be a result of several defects in genes that control heart muscle growth. 

    The Hypertrophic Cardiomyopathy Program

    The Hypertrophic Cardiomyopathy Program at Mount Sinai St. Luke's, run by Bette Kim, MD, specializes in evaluating and treating HCM. With more than 10 years of experience caring for patients with hypertrophic cardiomyopathy, our physicians continue to make important discoveries about the mechanisms of the disease, offering comprehensive diagnostic evaluations, a wide range of treatments, and screenings for family members who might be at risk.


    HCM doesn’t affect everyone the same way, with different degrees of muscular wall thickening and a variety of symptoms. Patients may experience shortness of breath, exercise intolerance, chest pressure or pain, fainting, or even no symptoms at all. In rare cases, adolescents and young adults — with no prior symptoms — can die suddenly without knowing that they have the disease. Hypertrophic cardiomyopathy is the most common heart condition that causes sudden death in young athletes and people under the age of 30.


    To properly diagnosis HCM, our cardiologists use echocardiography or sound wave imaging to photograph the heart and to determine the thickness of its muscle. Normally, heart walls are 11 mm or less in thickness, but patients with HCM have a characteristic thickening of the heart’s walls that can range from 14 to 60 mm.

    Patients with obstructive HCM usually have abnormal mitral valves. The mitral valve can move anteriorly, contact the thickened septal wall, and block blood from leaving the heart.

    In patients with unobstructive HCM, the ventricle walls thicken, but not in a way to impede blood flow out of the heart. Rather, the chambers can’t sufficiently relax to fill with blood, making the pumping action inefficient. Patients with unobstructive HCM can experience shortness of breath, chest pain, and blackouts. However, they are usually at low risk of developing complications or of dying, and often require no treatment.


    After a diagnosis of hypertrophic cardiomyopathy, each patient’s treatment plan is based on the severity of symptoms, whether they have obstructive or non-obstructive HCM, and any other mitigating circumstances.

    Most hypertrophic cardiomyopathy patients with symptoms can be treated successfully with medications. Patients with obstructions or symptoms that do not respond to medication generally benefit from surgery. Patients who don’t want surgery or have other illnesses that would complicate a surgical solution may benefit from pacemakers.

    Patients at risk for sudden death because of the presence of high-risk factors are treated with medication or implantable cardioverter defibrillators — devices that shock the heart back to a normal rhythm if a life-threatening irregular heartbeat occurs. Defibrillators are appropriate for only a minority of patients with HCM.

    How to Reach Us

    If you would like to learn more about Hypertrophic Cardiomyopathy Program, or to make an appointment with Dr. Bette Kim, please call 212-492-5550.

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    Hypertrophic Cardiomyopathy Program
    425 West 59th Street, Suite 9C
    New York, NY 10019

  • Pacemakers & Defibrillators

    Pacemakers and defibrillators are the two devices that can be implanted under the skin to treat arrhythmias.