Connect with others who understand.

Sign up Log in
Resources
About MyHeartDiseaseTeam
Powered By
See answer

Could It Be HCM? Symptoms and Causes of Hypertrophic Cardiomyopathy

Medically reviewed by Steven Kang, M.D.
Updated on April 5, 2024

  • Hypertrophic cardiomyopathy (HCM) causes the heart muscle to thicken, preventing the heart from pumping blood efficiently.
  • HCM is an inherited disease that runs in families.
  • People with HCM may not have any symptoms, or they may only have symptoms during or after vigorous physical activity.

Cardiomyopathies are diseases that occur in the heart muscle. One of the most common types of cardiomyopathy is hypertrophic cardiomyopathy. HCM is a genetic disease that causes the heart muscle to thicken and harden, which weakens the heart.

What Is Hypertrophic Cardiomyopathy?

HCM causes the walls of the heart’s left ventricle — one of the four chambers of the heart — to grow thicker (hypertrophy) and become stiff, making it more difficult for the heart to pump blood.

In a heart with hypertrophic cardiomyopathy, the walls of the left ventricle are thicker than those of a normal heart. They also can become stiff. (Adobe Stock)

When the walls of the heart grow thick, they can become less flexible and make the inside of the left ventricle smaller and stiffer. This prevents the left ventricle from properly filling with blood and efficiently pumping oxygen-rich blood to the body. Thickening of the left ventricle can interfere with heart valve function and may obstruct blood flow from the heart to the body.

HCM can progress and lead to heart failure and other complications, including:

  • Arrhythmia (irregular heartbeat or abnormal heart rhythms)
  • Heart failure
  • Stroke
  • Cardiac arrest

HCM can begin during childhood, but may not cause problems until much later in life.

Detecting HCM early in the disease’s progression can be difficult. It can also be hard to diagnose in people who are athletic. Exercise can strengthen the heart and make the left ventricle grow larger, which can mask the early stages of HCM.

HCM affects approximately 1 in 500 people in the United States. It runs in families and is the most common inherited heart condition.

What Are the Symptoms of Hypertrophic Cardiomyopathy?

Many people with HCM do not have any symptoms at all. When people do have symptoms, they may only occur during or after exercise or vigorous activity. If symptoms occur at rest, it may indicate more advanced disease.

Symptoms of HCM can include:

  • Chest pain
  • Shortness of breath
  • Fatigue
  • Dizziness or lightheadedness
  • Syncope (fainting)
  • Palpitations, faster heart rate, or a fluttering sensation in the chest
  • Irregular heartbeat
  • Cardiac arrest

People with HCM may have one or more of these symptoms or none at all. None of the symptoms of HCM are unique, and they can all occur with many other health conditions. If you have problems with breathing or heart symptoms, take them seriously and discuss them with your doctor.

Many people with hypertrophic cardiomyopathy do not have any symptoms at all. When people do have symptoms, they may only occur during or after exercise or vigorous activity.

Enter Cell 2 Content Here...

Enter Cell 3 Content Here...

Enter Cell 4 Content Here...

Enter Cell 5 Content Here...

Enter Cell 6 Content Here...

What Causes Hypertrophic Cardiomyopathy?

HCM is an inherited disease caused by gene mutations (changes in genes). Several genes have been identified that have mutations associated with HCM, including:

  • MYH7
  • MYBPC3
  • TNNT2
  • TNNI3

Each of these genes has a different function, but they are all involved in creating the proteins that make up the heart muscle.

Scientists believe that gene mutations associated with HCM cause abnormalities in the structure and function of heart tissue. Normally, heart muscle tissue grows in an orderly way, but in people with HCM, heart muscle fibers grow in a disorganized pattern.

Ultimately, this leads to the heart muscle growing thicker and stiffer, preventing the heart from relaxing and filling with blood as it should. HCM arrhythmias, such as atrial fibrillation (AFib), are irregular heart rhythms caused by abnormal electrical conduction through damaged heart muscle. Arrhythmias can sometimes lead to life-threatening complications, including blood clots, stroke, and cardiac arrest.

Along with left ventricular abnormalities, HCM can also affect the septum (wall) between the left and right ventricles. A thickened septum can obstruct blood flow into the aorta, the large artery that carries blood from the heart to the rest of the body. This is called obstructive hypertrophic cardiomyopathy.

Could You Have Hypertrophic Cardiomyopathy?

HCM is inherited in an autosomal dominant pattern. This means that you only need to inherit one copy of a mutated gene from one parent in order to develop the disease. A person with HCM has a 50 percent chance of passing this gene on to their child.

If you have a close family member with HCM, such as a parent, grandparent, or sibling, then you are at greater risk of having HCM. However, HCM may go undiagnosed in many people with a higher risk who do not have obvious symptoms of the condition.

If you have a close relative with hypertrophic cardiomyopathy, such as a parent, grandparent, or sibling, then you are at greater risk of having HCM.

Enter Cell 2 Content Here...

Enter Cell 3 Content Here...

Enter Cell 4 Content Here...

Enter Cell 5 Content Here...

Enter Cell 6 Content Here...

Even for someone who does have symptoms, diagnosing HCM can be difficult because symptoms of the condition are also seen in other medical conditions. Diagnosing HCM involves a thorough medical history and physical exam followed by imaging and laboratory tests such as echocardiogram, cardiac MRI, and genetic testing. A careful and accurate diagnosis of HCM is extremely important for determining the appropriate HCM treatment.

Sudden Cardiac Death

Some people with HCM may have a higher risk of sudden cardiac death (SCD, also called sudden cardiac arrest), though this is rare. Sudden cardiac death can also occur in people with undiagnosed HCM who have never had any symptoms.

If you know you’re at higher risk of having HCM or if you have a family history of SCD, talk to your doctor before participating in vigorous physical activity, such as football, basketball, soccer, or running. SCD mostly affects older people, but it can occur in young people participating in athletics. Sometimes, implantable cardioverter defibrillators (ICDs) are recommended to protect you from SCD.

Knowing the symptoms of HCM — and, more importantly, understanding your risk of developing the condition — can help you avoid serious complications of HCM. If you think you may be at risk of HCM, be sure to get medical advice before dangerous health issues arise.

Talk With Others Who Understand

MyHeartDiseaseTeam is the social network for people with heart disease and their loved ones. On MyHeartDiseaseTeam, more than 60,000 members come together to ask questions, give advice, and share their stories with others who understand life with heart disease.

Are you living with hypertrophic cardiomyopathy? Share your experience in the comments below, or start a conversation by posting on your Activities page.

Updated on April 5, 2024

A MyHeartDiseaseTeam Member

I've got question about my heart I'm 43 ex addict of methamphetamines. And the drs can't figure out what's wrong with me. I have these episodes only when I do physical work. It can be simple like… read more

May 24
All updates must be accompanied by text or a picture.

We'd love to hear from you! Please share your name and email to post and read comments.

You'll also get the latest articles directly to your inbox.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service.
All updates must be accompanied by text or a picture.

Subscribe now to ask your question, get answers, and stay up to date on the latest articles.

Get updates directly to your inbox.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service.

Could This Also Be Caused By A Mitral Valve Repair?

December 25, 2023 by A MyHeartDiseaseTeam Member
Steven Kang, M.D. is the Director of Cardiac Electrophysiology at Alta Bates Summit Medical Center and Alameda Health Systems in Oakland, California. Learn more about him here.
Kristopher Bunting, M.D. studied chemistry and life sciences at the U.S. Military Academy, West Point, and received his doctor of medicine degree from Tulane University. Learn more about him here.

Related Articles

The heart and lungs work closely together to keep your body healthy and functioning. If you have ...

Understanding How the Heart Affects the Respiratory System

The heart and lungs work closely together to keep your body healthy and functioning. If you have ...
Every time your heart beats, it pumps blood to the rest of your body. Structural heart disease is...

What Is Structural Heart Disease?

Every time your heart beats, it pumps blood to the rest of your body. Structural heart disease is...
Your heart and your kidneys may seem like unlikely partners, but they accomplish more together th...

Can Heart Failure Affect the Kidneys?

Your heart and your kidneys may seem like unlikely partners, but they accomplish more together th...
Every parent wants their child to live a happy, healthy life. But for parents of children with Do...

What To Know About Congenital Heart Disease and Down Syndrome

Every parent wants their child to live a happy, healthy life. But for parents of children with Do...
If you have hypertension (high blood pressure), your doctor may have talked to you about your ris...

Heart Failure and High Blood Pressure: What’s the Connection?

If you have hypertension (high blood pressure), your doctor may have talked to you about your ris...
After years of seeing yourself in the mirror, you’re probably pretty familiar with your appearanc...

Does a Crease in Your Earlobe Increase Your Risk for Heart Disease?

After years of seeing yourself in the mirror, you’re probably pretty familiar with your appearanc...

Recent Articles

If you’re living with a heart disease, you know there are many treatment options to consider. Alo...

Which Animals’ Heart Valves Are Used in Valve Replacement Surgery?

If you’re living with a heart disease, you know there are many treatment options to consider. Alo...
After your heart surgery, your focus is on healing and keeping your heart healthy. However, if yo...

Neuropathy After Heart Surgery: Causes and Treatments for Nerve Damage

After your heart surgery, your focus is on healing and keeping your heart healthy. However, if yo...
Are GLP-1 Drugs Safe for People With Heart Disease? Fact #1: GLP-1s Can Contribute To Heart ...

Are GLP-1 Drugs Safe for People With Heart Disease? 3 Facts To Know (VIDEO)

Are GLP-1 Drugs Safe for People With Heart Disease? Fact #1: GLP-1s Can Contribute To Heart ...
Coconut oil is often promoted for its health benefits, but its effects heart disease are still de...

Is Coconut Oil Safe for People With Heart Disease?

Coconut oil is often promoted for its health benefits, but its effects heart disease are still de...
If you’ve had a heart attack or have been diagnosed with cardiovascular disease, like atrial fibr...

5 Foods To Avoid When You Have Heart Disease

If you’ve had a heart attack or have been diagnosed with cardiovascular disease, like atrial fibr...
Do you ever take off your socks and notice deep indentations on your legs? Although you might not...

Are Sock Marks a Sign of High Blood Pressure?

Do you ever take off your socks and notice deep indentations on your legs? Although you might not...

Thank you for subscribing!

Become a member to get even more: