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Cardiomyopathy

Overview

Cardiomyopathy (kahr-dee-o-my-OP-uh-thee) is a disease of the heart muscle that makes it harder for your heart to pump blood to the rest of your body. Cardiomyopathy can lead to heart failure.

The main types of cardiomyopathy include dilated, hypertrophic and restrictive cardiomyopathy. Treatment — which might include medications, surgically implanted devices, heart surgery or, in severe cases, a heart transplant — depends on which type of cardiomyopathy you have and how serious it is.

Symptoms

There might be no signs or symptoms in the early stages of cardiomyopathy. But as the condition advances, signs and symptoms usually appear, including:

  • Breathlessness with activity or even at rest
  • Swelling of the legs, ankles and feet
  • Bloating of the abdomen due to fluid buildup
  • Cough while lying down
  • Difficulty lying flat to sleep
  • Fatigue
  • Heartbeats that feel rapid, pounding or fluttering
  • Chest discomfort or pressure
  • Dizziness, lightheadedness and fainting

Signs and symptoms tend to get worse unless treated. In some people, the condition worsens quickly; in others, it might not worsen for a long time.

When to see a doctor

See your doctor if you have one or more signs or symptoms associated with cardiomyopathy. Call 911 or your local emergency number if you have severe difficulty breathing, fainting or chest pain that lasts for more than a few minutes.

Some types of cardiomyopathy can be passed down through families (inherited). If you have the condition, your doctor might recommend that your family members be checked.

Causes

Dilated cardiomyopathy

Compared with a normal heart, a heart with dilated cardiomyopathy has enlarged chambers of the heart, which can lead to heart failure if left untreated.

Hypertrophic cardiomyopathy

Illustrations of a normal heart (left) and a heart with hypertrophic cardiomyopathy. Note that the heart walls (muscles) are much thicker (hypertrophied) in the heart with hypertrophic cardiomyopathy.

Often the cause of the cardiomyopathy is unknown. In some people, however, it's the result of another condition (acquired) or passed on from a parent (inherited).

Certain health conditions or behaviors that can lead to acquired cardiomyopathy include:

  • Long-term high blood pressure
  • Heart tissue damage from a heart attack
  • Long-term rapid heart rate
  • Heart valve problems
  • COVID-19 infection
  • Certain infections, especially those that cause inflammation of the heart
  • Metabolic disorders, such as obesity, thyroid disease or diabetes
  • Lack of essential vitamins or minerals in your diet, such as thiamin (vitamin B-1)
  • Pregnancy complications
  • Iron buildup in your heart muscle (hemochromatosis)
  • The growth of tiny lumps of inflammatory cells (granulomas) in any part of your body, including your heart and lungs (sarcoidosis)
  • The buildup of abnormal proteins in the organs (amyloidosis)
  • Connective tissue disorders
  • Drinking too much alcohol over many years
  • Use of cocaine, amphetamines or anabolic steroids
  • Use of some chemotherapy drugs and radiation to treat cancer

Types of cardiomyopathy include:

  • Dilated cardiomyopathy. In this type of cardiomyopathy, the pumping ability of your heart's main pumping chamber — the left ventricle — becomes enlarged (dilated) and can't effectively pump blood out of the heart.

    Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. The most common cause is coronary artery disease or heart attack. However, it can also be caused by genetic defects.

  • Hypertrophic cardiomyopathy. This type involves abnormal thickening of your heart muscle, which makes it harder for the heart to work. It mostly affects the muscle of your heart's main pumping chamber (left ventricle).

    Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it occurs during childhood. Most people with this type of cardiomyopathy have a family history of the disease. Some genetic mutations have been linked to hypertrophic cardiomyopathy.

  • Restrictive cardiomyopathy. In this type, the heart muscle becomes stiff and less flexible, so it can't expand and fill with blood between heartbeats. This least common type of cardiomyopathy can occur at any age, but it most often affects older people.

    Restrictive cardiomyopathy can occur for no known reason (idiopathic), or it can by caused by a disease elsewhere in the body that affects the heart, such as amyloidosis.

  • Arrhythmogenic right ventricular dysplasia. In this rare type of cardiomyopathy, the muscle in the lower right heart chamber (right ventricle) is replaced by scar tissue, which can lead to heart rhythm problems. It's often caused by genetic mutations.
  • Unclassified cardiomyopathy. Other types of cardiomyopathy fall into this category.

Risk factors

There are a number of things that can increase your risk of cardiomyopathy, including:

  • Family history of cardiomyopathy, heart failure and sudden cardiac arrest
  • Long-term high blood pressure
  • Conditions that affect the heart, including a past heart attack, coronary artery disease or an infection in the heart (ischemic cardiomyopathy)
  • Obesity, which makes the heart work harder
  • Long-term alcohol misuse
  • Illicit drug use, such as cocaine, amphetamines and anabolic steroids
  • Treatment with certain chemotherapy drugs and radiation for cancer

Many diseases also raise your risk of cardiomyopathy, including:

  • Diabetes
  • Thyroid disease
  • Storage of excess iron in the body (hemochromatosis)
  • Amyloidosis
  • Sarcoidosis
  • Connective tissue disorders

Complications

An enlarged heart

As your heart weakens, such as in heart failure, it begins to enlarge, which forces your heart to work harder to pump blood to the rest of your body.

Cardiomyopathy can lead to serious complications, including:

  • Heart failure. Your heart can't pump enough blood to meet your body's needs. Untreated, heart failure can be life-threatening.
  • Blood clots. Because your heart can't pump effectively, blood clots might form in your heart. If clots enter your bloodstream, they can block the blood flow to other organs, including your heart and brain.
  • Heart valve problems. Because cardiomyopathy causes the heart to enlarge, the heart valves might not close properly. This can cause blood to flow backward in the valve.
  • Cardiac arrest and sudden death. Cardiomyopathy can trigger abnormal heart rhythms that cause fainting or, in some cases, sudden death if your heart stops beating effectively.

Prevention

In many cases, you can't prevent cardiomyopathy. Let your doctor know if you have a family history of the condition.

You can help reduce your risk of cardiomyopathy and other types of heart disease by living a heart-healthy lifestyle and making lifestyle choices such as:

  • Avoiding the use of alcohol or cocaine
  • Controlling high blood pressure, high cholesterol and diabetes
  • Eating a healthy diet
  • Getting regular exercise
  • Getting enough sleep
  • Reducing your stress

Diagnosis

Your doctor will perform a physical examination and ask questions about your personal and family medical history. You'll also be asked when your symptoms occur — for example, whether exercise brings on your symptoms. If your doctor thinks you have cardiomyopathy, several tests may be done to confirm the diagnosis, including:

  • Chest X-ray. An image of your heart will show whether it's enlarged.
  • Echocardiogram. This test uses sound waves to create images of the heart, which show its size and its motions as it beats. This test checks your heart valves and helps your doctor determine the cause of your symptoms.
  • Electrocardiogram (ECG). In this noninvasive test, electrode patches are attached to your skin to measure electrical signals from your heart. An ECG can show disturbances in the electrical activity of your heart, which can detect abnormal heart rhythms and areas of injury.
  • Treadmill stress test. Your heart rhythm, blood pressure and breathing are monitored while you walk on a treadmill. Your doctor might recommend this test to evaluate symptoms, determine your exercise capacity and determine if exercise triggers abnormal heart rhythms.
  • Cardiac catheterization. A thin tube (catheter) is inserted into your groin and threaded through your blood vessels to your heart. Pressure within the chambers of your heart can be measured to see how forcefully blood pumps through your heart. Dye can be injected through the catheter into your blood vessels to make them more visible on X-rays (coronary angiogram). A cardiac catheterization can reveal blockages in your blood vessels.

    During this test, doctors can remove a small tissue sample (biopsy) from your heart for analysis in the laboratory.

  • Cardiac MRI. This test uses magnetic fields and radio waves to create images of your heart. Your doctor might order a cardiac MRI if the images from your echocardiogram aren't helpful in making a diagnosis.
  • Cardiac CT scan. You lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest to assess heart size and function and the heart valves.
  • Blood tests. Several blood tests might be done, including those to check your kidney, thyroid and liver function and to measure your iron levels.

    One blood test can measure B-type natriuretic peptide (BNP), a protein produced in your heart. Your blood level of BNP might rise when your heart is in heart failure, a common complication of cardiomyopathy.

  • Genetic testing or screening. Cardiomyopathy can be passed down through families (inherited). Ask your doctor if genetic testing is right for you. He or she might recommend family screening or genetic testing for your first-degree relatives — parents, siblings and children.

Treatment

The goals of cardiomyopathy treatment are to:

  • Manage your signs and symptoms
  • Prevent your condition from worsening
  • Reduce your risk of complications

The type of treatment you receive depends on which type of cardiomyopathy you have.

Medications

Many different types of medications are used to treat cardiomyopathy. Medications for cardiomyopathy can help:

  • Improve the heart's ability to pump blood
  • Improve blood flow
  • Lower blood pressure
  • Slow heart rate
  • Remove extra fluid from the body
  • Prevent blood clots

Therapies

Nonsurgical procedures used to treat cardiomyopathy or arrhythmia include:

  • Septal ablation. A small portion of the thickened heart muscle is destroyed by injecting alcohol through a long, thin tube (catheter) into the artery supplying blood to that area. This allows blood to flow through the area.
  • Radiofrequency ablation. To treat abnormal heart rhythms, doctors guide long, flexible tubes (catheters) through your blood vessels to your heart. Electrodes at the catheter tips transmit energy to damage a small spot of abnormal heart tissue that is causing the abnormal heart rhythm.

Surgery or other procedures

Several types of devices can be surgically implanted in the heart to improve its function and relieve symptoms, including:

  • Implantable cardioverter-defibrillator (ICD). This device monitors your heart rhythm and delivers electric shocks when needed to control abnormal heart rhythms. An ICD doesn't treat cardiomyopathy, but watches for and controls abnormal rhythms, a serious complication of the condition.
  • Ventricular assist device (VAD). This helps blood flow through your heart. A VAD usually is considered after less invasive approaches are unsuccessful. It can be used as a long-term treatment or as a short-term treatment while waiting for a heart transplant.
  • Pacemaker. This small device placed under the skin in the chest or abdomen uses electrical impulses to control arrhythmias.

Types of surgery used to treat cardiomyopathy include:

  • Septal myectomy. In this open-heart surgery, your surgeon removes part of the thickened heart muscle wall (septum) that separates the two bottom heart chambers (ventricles). Removing part of the heart muscle improves blood flow through the heart and reduces mitral valve regurgitation. Septal myectomy is used to treat hypertrophic cardiomyopathy.
  • Heart transplant. Your doctor might recommend a heart transplant if you have end-stage heart failure and medications and other treatments no longer work.

Lifestyle and home remedies

These lifestyle changes can help you manage cardiomyopathy:

  • Quit smoking.
  • Lose weight if you're overweight. Ask your doctor what a healthy weight is for you.
  • Get regular exercise, but talk to your doctor first about the safest type and amount for you.
  • Eat a healthy diet, including a variety of fruits and vegetables and whole grains.
  • Use less salt (sodium). Aim for less than 1,500 milligrams of sodium a day.
  • Avoid or drink less alcohol.
  • Try to manage your stress.
  • Get enough sleep.
  • Take all your medications as directed by your doctor.
  • Go to your doctor for regular follow-up appointments.

Preparing for an appointment

If you think you may have cardiomyopathy or are worried about your risk, make an appointment with your primary care doctor. He or she may refer you to a heart specialist (cardiologist).

Here's information to help you get ready for your appointment.

What you can do

Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.

Make a list of:

  • Your symptoms, including any that may seem unrelated to cardiomyopathy, and when they began
  • Key personal information, including a family history of cardiomyopathy, heart disease, stroke, high blood pressure or diabetes, and any major stresses or recent life changes
  • All medications, vitamins or other supplements you take, including doses
  • Questions to ask your doctor

Take a family member or friend along, if possible, to help you remember the information you're given.

For cardiomyopathy, some basic questions to ask your doctor include:

  • What's the most likely cause of my symptoms?
  • What are other possible causes?
  • What tests do I need?
  • What treatment options are available, and which do you recommend for me?
  • How often should I be screened?
  • Should I tell my family members to be screened for cardiomyopathy?
  • I have other health conditions. How can I best manage these conditions together?
  • Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you questions, including:

  • Do you have symptoms all the time, or do they come and go?
  • How severe are your symptoms?
  • What, if anything, seems to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
Last Updated: April 9th, 2021