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Last full review/revision Jul 2020| Content last modified Jul 2020
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What is cardiomyopathy?

"Cardio" refers to the heart. "Myopathy" refers to muscle that's not normal.

So cardiomyopathy is a heart disease that directly affects the heart muscle. Heart muscle is needed to pump blood.

  • A problem with your heart muscle keeps your heart from pumping blood properly

  • If your heart doesn't pump blood properly, you can be short of breath, weak and tired, and have swelling in your legs

  • Cardiomyopathy can be caused by certain heart infections, alcohol, certain medicines, or be an inherited heart muscle problem

  • Doctors do an ultrasound of your heart (echocardiography) and sometimes cardiac catheterization or MRI of your heart

  • Doctors will treat the cause of your cardiomyopathy and give you medicine to improve your heart's pumping, but sometimes you'll need heart surgery

Other diseases can stress and weaken your heart muscle. Examples include heart attacks, bad heart valves, and chronic high blood pressure. But these diseases aren't considered cardiomyopathy because they only indirectly affect your heart muscle. In cardiomyopathy, the problem starts in your heart muscle.

What are the types of cardiomyopathy?

There are 3 types of cardiomyopathy:

  • Dilated: Your heart enlarges (dilates) like a balloon

  • Hypertrophic: The walls of your heart become thick and stiff (hypertrophy)

  • Restrictive: The walls of your heart become stiff

What causes cardiomyopathy?

Often the cause of the cardiomyopathy is unknown. In some people, cardiomyopathy is caused by:

  • Certain viruses, such as coxsackie B virus or HIV, that can infect the heart

  • A bacterial heart infection called Chagas disease

  • Drinking too much alcohol for a long time

  • Certain medicines, particularly some chemotherapy drugs

  • An inherited problem that makes your heart muscle grow too thick in places

  • Body-wide diseases that cause material to build up in your heart muscle and make it stiff

  • Poorly controlled diabetes or thyroid disease

Body-wide diseases that cause material to build up in your heart muscle include amyloidosis, sarcoidosis, and hemochromatosis.

What are the symptoms of cardiomyopathy?

Cardiomyopathy may not cause symptoms at first. But eventually your heart stops pumping blood properly. This can cause heart failure symptoms:

  • Feeling short of breath

  • Getting tired easily

At first, you may notice symptoms only when you exert yourself.

Other symptoms can include:

  • Chest pain

  • Fainting

  • Abnormal heart rhythms

Hypertrophic cardiomyopathy can cause sudden death in young athletes. People may go into cardiac arrest with no warning.

How can doctors tell if I have cardiomyopathy?

To see if you have cardiomyopathy, doctors will do tests, such as:

  • Imaging tests, such as an MRI or echocardiography (an ultrasound of your heart)

  • Sometimes cardiac catheterization (doctors insert a thin, flexible tube in your heart's blood vessels), during which a small piece of heart tissue can also be taken (cardiac biopsy) and looked at under a microscope

  • Blood tests looking for a virus or body-wide conditions that can cause cardiomyopathy

How do doctors treat cardiomyopathy?

Doctors will treat the cause of your cardiomyopathy if possible. For example, if you have Chagas disease, you'll get antibiotics. If you have hemochromatosis, you'll get treatments to remove excess iron from your body.

Different types of cardiomyopathy need different treatments, but these may include:

If your heart keeps getting weaker despite these treatments, you may need a heart transplant. If you have certain kinds of hypertrophic cardiomyopathy, surgically removing some of the thickened heart muscle may help.

Doctors may also suggest that you:

  • Lower your stress

  • Eat less salt

  • Avoid exercise if you have hypertrophic cardiomyopathy

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