What Is Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is a condition in which your
heart muscle, or myocardium, becomes thicker than normal. This interferes with
your heart’s ability to pump blood.
In most cases, HCM doesn’t cause any symptoms. People with HCM
are generally able to lead normal lives. However, some cases can become
serious. Serious cases may develop either slowly or suddenly.
HCM occurs in about one in every 500
people in the United States.
Recognizing the Symptoms of HCM
Many people with HCM don’t experience any symptoms. However, the
following symptoms may occur during physical activity:
- chest pain
- shortness of breath
Other symptoms that might occur, at any time, include:
- shortness of breath
- heart palpitations, which are pounding or
- high blood pressure
What Causes HCM?
HCM is typically an inherited condition. Defective genes can cause
your heart muscle to thicken. You have a 50
percent chance of inheriting one of these genes if one of your parents is
affected by HCM.
Inheriting the gene doesn’t necessarily mean that you’ll have
symptomatic disease. HCM follows a dominant pattern of inheritance. However,
symptoms don’t always develop in people with the defective gene.
Other possible causes of HCM include aging and high blood
pressure. In some cases, the cause of HCM is never identified.
How Is HCM Diagnosed?
Different tests can be used to diagnose HCM.
Your doctor will listen for a heart murmur or unusual heartbeats.
Heart murmurs may occur if thickened heart muscle disrupts blood flow to your
This is the most common diagnostic test for HCM. An
echocardiogram creates images of your heart using sound waves. Your doctor will
look for any unusual movements.
An electrocardiogram is used to measure the electrical activity
in your heart. HCM can cause abnormal results.
A Holter monitor is a portable electrocardiogram that you can
wear throughout the day. Your doctor will have you wear it for 24 to 48 hours.
This allows your doctor to see how your heartbeat changes during different
A cardiac MRI uses a magnetic field to produce detailed images of
This test is used to measure the pressure of blood flow in your
heart and look for blockages. To perform this test, your doctor will place a
catheter in one of your arteries in your arm or near your groin. The catheter
is carefully threaded up through your arteries to your heart. Once it reaches
your heart, dye is injected so your doctor can take detailed X-ray images.
How Is HCM Treated?
Treatment for HCM focuses on relieving symptoms and preventing
complications, especially sudden cardiac death. The methods used depend on
- activity level
- heart function
Beta-blockers and calcium channel blockers relax your heart
muscle. Relaxation helps it work better.
If you have an irregular heart rhythm, your doctor might
prescribe antiarrhythmic medications, such as amiodarone.
You might need to take antibiotics before dental procedures or
surgery to lower your risk of infective endocarditis.
A septal myectomy is an open-heart surgery that’s done to remove
part of your thickened septum. The septum is the heart muscle wall between your
two lower heart chambers, which are your ventricles. It helps improve blood
flow through your heart.
A septal myectomy is done only if medications don’t reduce your
Septal ablation involves the use of alcohol to destroy part of your
thickened heart muscle. The alcohol is injected through a catheter placed in
the artery that supplies the part of your heart that’s being treated.
A septal ablation is often done in people who can’t have a septal
If you have an irregular heart rate and rhythm, a tiny electronic
device called a pacemaker can be placed under the skin on your chest. The
pacemaker helps regulate your heart rate by sending electrical signals to your
This procedure is less invasive than septal myectomies and
ablations. It’s also usually less effective.
Implantable Cardioverter Defibrillator (ICD)
An implantable cardioverter defibrillator (ICD) is a small device
that uses electric shocks to track your heartbeat and fix dangerous, abnormal heart
rhythms. It’s placed inside your chest.
ICD is often used in people who have a high risk of sudden
If you have HCM, your doctor may recommend lifestyle changes to
reduce your risk of complications. This includes:
- eating a healthy diet
- keeping your weight at a healthy level
- doing low-intensity physical activities
- limiting alcohol intake, since alcohol can cause
abnormal heart rhythms
Potential Long-Term Complications of HCM
Many people with HCM will never have any serious health problems
caused by it. However, HCM can cause severe complications in some people. The
most common complications of HCM are:
Sudden Cardiac Arrest
Sudden cardiac arrest occurs when your heart suddenly stops
working. This condition is also called “sudden cardiac death.” This is
typically caused by a rapid heart rhythm known as ventricular tachycardia.
Without emergency treatment, sudden cardiac arrest can be fatal. HCM is the
leading cause of sudden cardiac death in people who are under 30.
You might be at higher risk for sudden cardiac death if you have
one or more of the following:
- a family history of sudden cardiac death
- poor heart function
- severe symptoms
- a history of irregular heart rhythms with a fast
- a history of fainting on several occasions and
- an unusual blood pressure response to physical
When your heart doesn’t pump the amount of blood that your body
needs, you’re experiencing heart failure.
This diagnosis means your heart muscle has become weak and
enlarged. The enlargement makes your heart work less effectively.
When the inner lining of your heart or your heart valves become
infected, it’s known as infective endocarditis. This can happen when bacteria
or fungi enter your bloodstream and get into your heart. Infective endocarditis
can cause tissue scarring, holes, or growths in your heart valves. It can be
fatal without treatment.
Coping and Getting Support
Having a disease like severe HCM can raise your risk of emotional
problems. Some people have trouble coping with the adjustments they have to
make, such as restricting exercise and relying on medication for the rest of
If you’re having difficulty coping with HCM, your doctor might
recommend seeing a therapist or joining a support group. You might also benefit
from medications used to treat anxiety or depression.