Hypertrophic cardiomyopathy (HCM) is a rare condition that occurs when your heart muscle becomes abnormally thick.
This condition develops due to a genetic change that affects your heart’s muscle proteins, which are critical in helping your heart function properly. In some cases, the thickened muscle can block the ventricles (the heart’s lower chambers), making it difficult for your heart to pump blood efficiently.
This thickening of the heart muscle can lead to a few key problems, like a lack of blood flow to your heart and heart valves that stop functioning as needed.
As a result, you may experience symptoms like fatigue, shortness of breath, and chest pain, among others. In rare cases—particularly among young athletes- HCM can lead to sudden cardiac death, which is why understanding and managing this condition is so important.
When HCM first develops, it’s possible that you don’t experience any symptoms at all. However, as the condition progresses and blood flow in the heart reduces, you may experience the following symptoms:
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- Chest pain that worsens with physical activity
- Shortness of breath
- Fatigue
- Fainting
- Arrhythmias (or, an irregular heartbeat)
- Heart palpitations
- Dizziness
- Swelling in the ankles, feet, legs, and abdomen
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This heart condition can run in families and you can inherit it through an “autosomal dominant” pattern, which means that there is about a 50% chance of a child inheriting the condition from a parent who has it. HCM typically occurs due to genetic mutations (or changes) in the genes that are responsible for making heart muscle proteins. These proteins play an important role in helping your heart contract and relax.
So far, scientists have identified several gene mutations that are linked to HCM. The specific mutation you have can determine the exact symptoms your experience and how thick your heart muscle can become.
- If you suspect you have HCM or have a family history of this condition, it’s important to see your healthcare provider for a thorough cardiac (heart) evaluation. During your appointment, your provider will ask about your medical history, learn about the symptoms you’re experiencing, and perform a physical exam. To confirm a diagnosis, your provider may also order one or more of the following tests:
- Electrocardiogram (ECG): Shows changes in your heart activity, such as alterations in your heart’s electrical patterns and specific heart waves that can suggest the presence of HCM
- Transthoracic echocardiogram (TTE): Uses ultrasound to create detailed images of your heart’s structure and pumping function to understand how well the heart valves are working and to measure the mass and wall thickness of your left ventricle
- Ambulatory ECG monitoring: Continuously monitors your heart activity, usually for 24 to 48 hours to assess the risk of dangerous heart rhythms
- Exercise stress testing: Involves exercising under medical supervision to evaluate how well your heart responds to physical stress
