Symptoms of hypertrophic cardiomyopathy can include one or more of the following:

• Shortness of breath, mainly during exercise.
• Chest pain, mainly during exercise.
• Fainting, mainly during or just after exercise or other physical activity.
• The feeling of fast, fluttering or pounding heartbeats called palpitations.

When to see a doctor

Many conditions can cause shortness of breath and fast, pounding heartbeats. It's important to get a checkup right away to find the cause of your symptoms and get the right care. See your healthcare professional if you have a family history of HCM or any symptoms related to hypertrophic cardiomyopathy.

Call 911 or your local emergency number if you have any of the following symptoms for more than a few minutes:

• A very fast or irregular heartbeat.
• Trouble breathing.
• Chest pain.

Hypertrophic cardiomyopathy (HCM) usually is caused by changes in genes that cause the heart muscle to thicken.

Hypertrophic cardiomyopathy typically affects the muscular wall between the two bottom chambers of the heart. This wall is called the septum. The chambers are called the ventricles. The thickened wall might block blood flow out of the heart. When this happens, the condition is called obstructive hypertrophic cardiomyopathy.

If there's little or no blocking of blood flow, the condition is called nonobstructive hypertrophic cardiomyopathy. But the heart's main pumping chamber, called the left ventricle, might get stiff. This makes it hard for the heart to relax. The stiffness means the ventricle can’t fill with as much blood, so there’s less blood for the heart to pump out with each beat.

Heart muscle cells also become arranged differently in people with hypertrophic cardiomyopathy. This is called myofiber disarray. It can cause irregular heartbeats in some people.

Hypertrophic cardiomyopathy usually is passed down through families. That means it's inherited. People with one parent with hypertrophic cardiomyopathy have a 50% chance of having the gene change that causes the disease.

Parents, children or siblings of a person with hypertrophic cardiomyopathy should ask their healthcare team about screening tests for the disease.

Complications of hypertrophic cardiomyopathy (HCM) can include:

• Atrial fibrillation. A thickened heart muscle and changes in the structure of heart cells can cause an irregular and often very fast heartbeat called atrial fibrillation (AFib). AFib also raises the risk of blood clots, which can travel to the brain and cause a stroke.
• Blocked blood flow. In many people with HCM, the thickened heart muscle blocks the blood flow leaving the heart. This can cause shortness of breath with activity, chest pain, dizziness and fainting spells.
• Mitral valve disease. If the thickened heart muscle blocks the blood flow leaving the heart, the valve between the left heart chambers might not close properly. That valve is called the mitral valve. When the valve doesn't close as it should, blood can go backward into the left upper chamber. This is a condition called mitral valve regurgitation. It might make hypertrophic cardiomyopathy symptoms worse.
• Dilated cardiomyopathy. In a small number of people with HCM, the thickened heart muscle becomes weak and doesn't work well. Dilated cardiomyopathy tends to start in the left lower heart chamber. The chamber becomes larger, and the heart pumps with less force.
• Heart failure. Over time, the thickened heart muscle can become too stiff to fill the heart with blood. As a result, the heart can't pump enough blood to meet the body's needs.
• Fainting, also called syncope. An irregular heartbeat or blockage of blood flow sometimes can cause fainting. Fainting for no a clear reason can be related to sudden cardiac death, especially if it's happened recently and in a young person.
• Sudden cardiac death. Rarely, hypertrophic cardiomyopathy can cause heart-related sudden death in people of all ages. Many people with hypertrophic cardiomyopathy don't realize they have HCM. As a result, sudden cardiac death might be the first sign of the condition. Sudden cardiac death can happen in young people who seem healthy, including high school athletes and other young, active adults.

There is no known way to prevent hypertrophic cardiomyopathy (HCM). It's important to find the condition with tests as early as possible. Test results can guide treatment and prevent complications.

Hypertrophic cardiomyopathy usually is passed down in families. If you have a parent, brother or sister with hypertrophic cardiomyopathy, ask your healthcare team if genetic screening is right for you. But not everyone with HCM has a gene change that tests can find. Also, check with your insurer to see if genetic testing is a covered expense.

If genetic testing isn't done, or if the results aren't helpful, screening may be done with repeated echocardiograms. An echocardiogram is an imaging test that uses sound waves to make pictures of the heart.

For people who have a family member with hypertrophic cardiomyopathy:

• Echocardiogram screenings are recommended starting at about age 12.
• Screenings with echocardiograms should continue every 1 to 3 years through ages 18 to 21.
• After that, the screenings can be done every five years through adulthood.

You may need to have an echocardiogram more often based on your overall health and healthcare team's preference.

To diagnose hypertropic cardiomyopathy (HCM), a healthcare professional examines you and listens to your heart with a device called a stethoscope. The device may help your healthcare professional hear a heart murmur while listening to the heart.

A member of your healthcare team usually asks questions about your symptoms and your medical and family history.

Tests

Healthcare professionals do tests to check the heart and look for causes of any symptoms.

• Echocardiogram. This imaging test often is used to diagnose hypertrophic cardiomyopathy. It uses sound waves to make images of the beating heart. An echocardiogram shows how well the heart's chambers and valves are pumping blood. It also can see if the heart's muscle is thicker than it should be.
• Electrocardiogram (ECG or EKG). This quick and painless test shows how the heart is beating. Sticky patches with sensors on them called electrodes go on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which prints or shows the test results. An ECG can show irregular heartbeats and signs of heart thickening.
• Holter monitor. This small, portable ECG device records the heart's activity. It's worn for a day or two while you do your regular activities.
• Cardiac MRI. This test uses powerful magnets and radio waves to create images of the heart. It gives details about the heart muscle and how the heart and heart valves work. This test often is done with an echocardiogram.
• Stress test. A stress test often involves walking on a treadmill or riding a stationary bike while a healthcare professional watches your heart activity. Exercise stress tests help reveal how the heart responds to physical activity.
• Genetic testing or counseling. Hypertrophic cardiomyopathy usually is passed down in families. Ask your healthcare professional if genetic testing is right for you.
• Cardiac CT scan. Rarely, this test is done to diagnose hypertropic cardiomyopathy. But it may be suggested if an MRI can't be used. A cardiac CT scan uses X-rays to make pictures of the heart and chest. It can show the size of the heart.

Lifestyle changes can lower the risk of complications related to hypertrophic cardiomyopathy. Try these healthy habits:

• Exercise. Staying active keeps the heart healthy. Talk with your healthcare team about the amount and type of exercise that's best for you.
• Eat a healthy diet. Eat plenty of fruits, vegetables and whole grains. Limit sugar, salt and saturated fats.
• Don't smoke. Smoking is a major risk factor for heart disease. If you smoke and can't quit, talk with your healthcare team about programs or treatments that can help.
• Stay at a healthy weight. Being overweight strains the heart and increases the risk of heart disease. Ask your healthcare professional what weight is best for you.
• Limit or stay away from alcohol. Sometimes, irregular heartbeats and blocked blood flow are triggered or made worse by alcohol use. Ask your healthcare professional how much alcohol, if any, is safe for you to drink. Keep in mind that all types of heavy drinking are linked to worse heart health. That includes binge drinking, which means having four or more drinks for women, or five or more drinks for men, within about two hours.
• Manage blood pressure and cholesterol. High blood pressure and high cholesterol raise the risk of heart disease. Make lifestyle changes and take medicines as directed to manage either condition. Get regular health checkups. Your healthcare professional might recommend regular follow-up appointments to check on your condition. Tell your care team if you have new symptoms or if your symptoms become worse.
• Practice good sleep habits. Poor sleep may raise the risk of heart disease and other long-term conditions. Adults should try to get 7 to 9 hours of sleep daily. Go to bed and wake at the same time every day, including on weekends. If you have trouble sleeping, talk to a healthcare professional about treatments or changes that might help.

Connect with friends and family or a support group. You may find that talking about hypertrophic cardiomyopathy with other people who have heart conditions can help.

It's also important to manage your stress. Some good ways to do that are to get more exercise and practice mindfulness. If you have anxiety or depression, talk to your healthcare team about treatments that can help.

You may be referred to a doctor trained in heart diseases, called a cardiologist. Here's some information to help you prepare for your appointment.

What you can do

When you make the appointment, ask if you need to follow any restrictions before the checkup. For instance, you may need to change your activity level or your diet. Make a list of:

• Your symptoms and when they began.
• All medicines, vitamins and supplements you take, including doses.
• Important medical information, including other conditions you have and any family history of heart disease.
• Questions to ask your healthcare professional.

Questions to ask your healthcare professional might include:

• What's the most likely cause of my symptoms?
• What tests do I need?
• What treatments can help?
• What risks does my heart condition create?
• How often do I need health checkups?
• Do I need to change my activities?
• What's an appropriate level of physical activity?
• Should my children or other first-degree relatives be screened for this condition, and should I meet with a genetic counselor?
• I have other health conditions. How do I manage them together?

Feel free to ask other questions you have.

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

• How bad are your symptoms?
• Have your symptoms changed over time? If so, how?
• Does exercise or physical activity make your symptoms worse?
• Have you ever fainted?

What you can do in the meantime

Before your appointment, ask your family members if any relatives have been diagnosed with hypertrophic cardiomyopathy or have died suddenly without a clear cause.

If exercise makes your symptoms worse, don't do strenuous exercise until you have seen your healthcare professional. Ask for specific exercise recommendations.