Hypertrophic Cardiomyopathy (HCM) | Symptoms & Treatment | MedStar Health

A genetic condition that causes heart muscle tissue to become abnormally thick

Hypertrophic cardiomyopathy (HCM) affects about one in 500 people. If the heart muscle tissue thickens too much, it can obstruct the flow of blood out of the heart or prevent the heart from pumping enough blood to the rest of the body. In severe cases, it can lead to heart failure or sudden cardiac death. HCM also can cause an arrhythmia, or irregular heartbeat.

If you or a family member is diagnosed with hypertrophic cardiomyopathy, you may want to consider genetic testing to determine whether you’re at risk for the condition or at risk of passing it on to your children. You may also want to make an appointment with the specialists at the Hypertrophic Cardiomyopathy Clinic, located at MedStar Heart & Vascular Institute at MedStar Union Memorial Hospital. This clinic offers comprehensive, coordinated care for HCM patients across multiple specialties.

What are the symptoms of HCM?

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

Other symptoms of HCM may include:

  • Chest pain

  • Fatigue

  • Feeling dizzy, light-headed, or faint

  • Heart palpitations, described as a fluttering or pounding in your chest

  • Shortness of breath


Diagnosing hypertrophic cardiomyopathy can be challenging, as heart muscle thickening also can be caused by high blood pressure or extreme athletic conditioning. Your doctor will perform a complete physical exam and listen for abnormal sounds in the heart. They also will analyze thickened heart muscle and problems with blood flow or heart valves

Angiogram (Angiography)

An angiogram is a special X-ray taken as a special dye is injected through a thin, flexible tube called a catheter to detect blockages or aneurysms in blood vessels.

Cardiac Catheterization

Cardiac catheterization is a minimally invasive way to diagnose and treat a variety of heart and vascular conditions by guiding thin, flexible tubes called catheters through blood vessels to problem areas.

Chest X-ray

Chest X-rays use a small dose of radiation to create pictures of the structures inside the chest, including the lungs, heart, and chest wall.

Computerized Tomography (CT) Scan

The cardiac computed tomography scan, or cardiac CT, uses X-rays to create three-dimensional images of your heart and blood vessels.


An echocardiogram uses high-frequency sound waves to create images of your heart.

Electrocardiogram (ECG)

An electrocardiogram, also known as an ECG, measures the heart’s electrical activity.

Event Monitors

An event monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but whereas an electrocardiogram takes place over a few minutes, an event monitor measures heart rhythms over a much longer time.

Holter Monitors

A Holter monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but whereas an electrocardiogram records over a few minutes, a Holter monitor records over the course of a day or two.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging, better known as cardiac MRI, is a combination of radio waves, magnets, and computer technology to create images of your heart and blood vessels.

Stress Tests

Stress tests are used to assess how your heart works during physical activity. There are several types of stress tests, including treadmill or bike stress tests, nuclear stress tests, stress echocardiograms, and chemically induced stress tests.


If your HCM symptoms are not adequately controlled with medications, open heart surgery or a minimally invasive procedure called alcohol septal ablation may be recommended to reduce obstruction to blood flow. If you are deemed to be at high risk for life-threatening arrhythmias, your doctor may recommend implanting a defibrillator.

Alcohol Septal Ablation

Alcohol septal ablation, also known as septal alcohol ablation, is a minimally invasive procedure our doctors use to treat hypertrophic cardiomyopathy. The procedure shrinks abnormal tissue and improves blood flow throughout the body.

Implantable Cardioverter Defibrillator (ICD)

An implantable cardioverter defibrillator (ICD) is a device implanted below your collarbone that monitors your heart’s rhythm. When it detects an abnormal rhythm, it delivers an electrical impulse or shock to the heart to correct it.

Septal Myectomy

Septal myectomy is a surgical procedure to remove overgrown heart muscle and improve blood flow through the heart.

Ask MedStar Heart & Vascular Institute

Have general questions for our heart and vascular program? Email us at AskMHVI@medstar.net. If you have clinically-specific questions, please contact your physician’s office.