What Is Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) is a condition affecting the left ventricle, the main pumping chamber of the heart. The walls of the left ventricle become thick and stiff. Over time, the heart can't take in or pump out enough blood during each heartbeat to supply the body's needs.

HCM is usually caused by an inherited genetic variant (familial hypertrophic cardiomyopathy).

HCM can lead to many serious health conditions, such as:

It is a major cause of sudden cardiac death in people younger than 35.

Types of Hypertrophic Cardiomyopathy

There are two main types of HCM:

  • Obstructive: The most common type, hypertrophic obstructive cardiomyopathy (HOCM) means the wall (septum) between the left ventricle and right ventricle thickens. This can block (obstruct) blood flow from the left ventricle to the aorta (the body's main artery).
  • Nonobstructive: In nonobstructive HCM, the heart muscle thickens but doesn't block blood flow.

Hypertrophic Cardiomyopathy Symptoms

The signs and symptoms of HCM can vary widely, even among members of the same family. Some people may have no symptoms at all, but others can experience:

  • Arrhythmia (irregular heart rate or rhythm)
  • Chest pain, especially during activity
  • Fatigue
  • Fluttering or pounding feeling in the chest
  • Heart murmur
  • Lightheadedness or dizziness
  • Fainting
  • Shortness of breath, especially during activity
  • Swelling in the feet, ankles, legs, belly or neck

Symptoms tend to get worse over time, eventually lowering your ability to perform everyday activities and responsibilities.

Diagnosis of Hypertrophic Cardiomyopathy

If you have symptoms of HCM or a family history of heart problems, it's important to talk to an expert in inherited cardiac disease. Even people with no symptoms can have life-threatening complications from HCM.

If you are evaluated for HCM at Penn, you'll have:

  • Physical exam and medical history: We ask you detailed questions about your medical history and family medical history. Then we do a thorough exam to look for features of hypertrophic cardiomyopathy.
  • Cardiac MRI:This tool takes images of the heart to detect any thickening of the left ventricle's wall.
  • Coronary angiography: This test takes images of the coronary arteries (blood vessels) to see if they have blockages.
  • Echocardiogram (echo): This test uses ultrasound waves to take pictures of the heart. It can measure the thickness of the heart muscle as well as how well your heart is pumping blood.
  • Electrocardiogram (ECG): This test records the electrical impulses in the heart and can detect any abnormal rate or rhythm.
  • Electrophysiology study: An electrophysiologist inserts a thin tube through a blood vessel and into the heart to measure electrical activity.
  • Genetic testing and counseling: A blood test evaluates the genes involved in HCM. A genetic specialist can help you determine whether you or your family members should get genetic testing. Anyone having genetic testing should also have genetic counseling. A trained counselor can help you understand the process and what it might mean for you and your family.
  • Holter monitor: This is a wearable device that monitors the heart's electrical activity as you go about your daily activities.
  • Stress test: Also called an exercise test, this measures heart function while you're walking or running on a treadmill.

Hypertrophic Cardiomyopathy Treatment at Penn

There's no cure for HCM, but consistent monitoring can identify problems before they interfere with your health. Appropriate treatment can help you feel better and protect you from complications.

Treatment for HCM symptoms often focuses on protecting the heart. Some medications can make it easier for the heart to pump as it should.

Depending how severe it is, your treatment may include:

The Penn network has specialists with extensive training and experience in cardiomyopathy and all its possible treatments. They work together to personalize your treatment. Your Penn Medicine team may include experts in:

Penn Programs & Services for Hypertrophic Cardiomyopathy

Happy family at a picnic
Center for Inherited Cardiovascular Disease

Inherited cardiac disease affects multiple generations. The Penn Center for Inherited Cardiovascular Disease provides comprehensive care for genetic heart conditions.

Maurice Howerton

Maurice's Story

Hypertrophic Cardiomyopathy

The last thing Maurice remembers about that day was sipping from a bottle of Gatorade during a break in their fourth game. Without warning, he collapsed onto the court.

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