Hypertrophic cardiomyopathy (HCM) is a genetic condition (occurring in about 1 of 500 people) that causes heart muscle tissue to thicken. If the muscle tissue thickens too much, it can block blood flow from the heart to the rest of the body.

HCM can also cause you to have arrhythmia, an irregular heartbeat. If your arrhythmia is potentially life threatening, your doctor may implant a defibrillator to protect your heart.

If medication does not reduce your symptoms, you may need to have open heart surgery. This procedure will cut out the thickened tissue and improve your blood flow. 

Other conditions, such as high blood pressure (hypertension) or extreme athletic conditioning, can cause heart muscle thickening. This abnormal tissue may resemble HCM, making a diagnosis more challenging.


Many people who have HCM may not realize it because they often have no symptoms. During a routine medical exam, your physician may discover a heart murmur or suspect HCM after an abnormal electrocardiogram (ECG). But sometimes, the first symptom is a sudden collapse or cardiac arrest.

Other symptoms that people with HCM may experience include:

  • Shortness of breath, most commonly during activity
  • Dizziness, light-headedness or fainting during or after physical activity
  • Chest pain
  • Fatigue
  • Heart palpitations (fluttering or pounding in your chest)

Diagnosis and Treatment

Your physician will perform a complete physical exam and listen for abnormal sounds in the heart. These sounds include an abnormal heartbeat or a heart murmur. At MedStar Heart & Vascular Institute, our cardiac team looks for thickened heart muscle and problems with blood flow or heart valves using the following tests:

  • Echocardiogram (most common) to diagnose and monitor HCM
  • Electrocardiogram (ECG)
  • Diagnostic imaging, including Cardiovascular MRI
  • Cardiac catheterization to evaluate the function of your heart's arteries, chambers and valves
  • Event monitor to record your heart rhythm over time
  • Genetic testing to detect mutations known to cause HCM

If your physician diagnoses you or a family member with HCM, screening of other family members is very important. We offer genetic screening for heart conditions.

For people with HCM, our treatment goals focus on controlling symptoms, managing related conditions and preventing sudden cardiac arrest. Our cardiac specialists may recommend one or more of these treatment options:

  • Medications such as beta blockers, calcium channel blockers or anti-arrhythmic drugs to help regulate heart contractions
  • Surgery to implant a pacemaker to regulate your heartbeat or a defibrillator to correct dangerous heart arrhythmia
  • Open-heart surgery to remove parts of the thickened muscle or replace heart valves
  • Cardiac catheterization for septal alcohol ablation to remove excess muscle tissue in the heart
  • Lifestyle changes, including avoiding very strenuous activity

Call Us Today

To find a heart specialist, call:

877-74-HEART (43278)