Cardiomyopathy

Overview

Cardiomyopathy (kahr-dee-o-my-OP-uh-thee) is a disease of the heart muscle that makes it harder for the heart to pump blood to the rest of the 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 the type of cardiomyopathy 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 health care provider 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 health care provider might recommend that your family members be checked.

Causes

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 the diet, such as thiamin (vitamin B-1)
  • Pregnancy complications
  • Iron buildup in the heart muscle (hemochromatosis)
  • The growth of tiny lumps of inflammatory cells (granulomas) in any part of the body, including the 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 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 changes.

  • Hypertrophic cardiomyopathy. This type involves abnormal thickening of the heart muscle, which makes it harder for the heart to work. It mostly affects the muscle of the 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 changes 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 changes.
  • Unclassified cardiomyopathy. Other types of cardiomyopathy fall into this category.
Dilated cardiomyopathy

Dilated cardiomyopathy causes the chambers of the heart to grow larger. Untreated, dilated cardiomyopathy can lead to heart failure.

Hypertrophic cardiomyopathy

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

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

Cardiomyopathy can lead to serious complications, including:

  • Heart failure. The heart can't pump enough blood to meet the body's needs. Untreated, heart failure can be life-threatening.
  • Blood clots. Because the heart can't pump effectively, blood clots might form in the heart. If clots enter the bloodstream, they can block the blood flow to other organs, including the 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 irregular heart rhythms that cause fainting or, in some cases, sudden death if the heart stops beating effectively.
Enlarged heart, in heart failure

As the heart weakens, as it can in heart failure, it begins to enlarge, forcing your heart to work harder to pump blood on to the rest of your body.

Prevention

In many cases, there's no prevention for cardiomyopathy. Let your health care provider 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, including:

  • 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 health care provider is likely to 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 triggers your symptoms. If your provider thinks you have cardiomyopathy, several tests may be done to confirm the diagnosis, including:

  • Chest X-ray. An image of the 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 the heart valves and helps determine the cause of symptoms.
  • Electrocardiogram (ECG). In this noninvasive test, electrode patches are attached to the skin to measure electrical signals from the heart. An ECG can show disturbances in the electrical activity of the heart, which can detect irregular heart rhythms and areas of injury.
  • Treadmill stress test. Heart rhythm, blood pressure and breathing are monitored while walking on a treadmill. This test can evaluate symptoms, determine exercise capacity and whether exercise triggers irregular heart rhythms.
  • Cardiac catheterization. A thin tube (catheter) is inserted into the groin and threaded through blood vessels to the heart. Pressure within the chambers of the heart can be measured to see how forcefully blood pumps through the heart. Dye can be injected through the catheter into blood vessels to make them more visible on X-rays (coronary angiogram). Cardiac catheterization can reveal blockages in blood vessels.

    This test might also involve removal of a small tissue sample (biopsy) from the heart for laboratory analysis.

  • Cardiac MRI. This test uses magnetic fields and radio waves to create images of the heart. A provider might order a cardiac MRI if the images from an echocardiogram aren't helpful in making a diagnosis.
  • Cardiac CT scan. This involves lying on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around the body and collects images of the 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 kidney, thyroid and liver function and to measure iron levels.

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

  • Genetic testing or screening. Cardiomyopathy can be passed down through families (inherited). Ask your health care provider if genetic testing is right for you. Family screening or genetic testing might include first-degree relatives — parents, siblings and children.

Treatment

The goals of cardiomyopathy treatment are to:

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

The type of treatment depends on the type of cardiomyopathy and its severity.

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 irregular heart rhythms, health care providers guide long, flexible tubes (catheters) through blood vessels to the heart. Electrodes at the catheter tips transmit energy to damage a small spot of heart tissue that is causing the irregular 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 heart rhythm and delivers electric shocks when needed to control irregular heart rhythms. An ICD doesn't treat cardiomyopathy; rather it watches for and controls irregular rhythms, a serious complication of the condition.
  • Ventricular assist device (VAD). This helps blood flow through the 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, a 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. A heart transplant might be for people with end-stage heart failure for whom 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 health care provider what a healthy weight is for you.
  • Get regular exercise after talking to your provider 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 prescribed.
  • See your provider 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 health care provider. 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 provider

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 provider 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 that 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 Apr 2, 2022


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