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 or, in severe cases, a heart transplant — depends on which type of cardiomyopathy you have and how serious it is.
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 exertion or even at rest
- Swelling of the legs, ankles and feet
- Bloating of the abdomen due to fluid buildup
- Cough while lying down
- 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.
Because some types of cardiomyopathy can be hereditary, if you have it your doctor might advise that your family members be checked.
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).
Contributing factors for acquired cardiomyopathy include:
- Long-term high blood pressure
- Heart tissue damage from a heart attack
- Chronic rapid heart rate
- Heart valve problems
- Metabolic disorders, such as obesity, thyroid disease or diabetes
- Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1)
- Pregnancy complications
- Drinking too much alcohol over many years
- Use of cocaine, amphetamines or anabolic steroids
- Use of some chemotherapy drugs and radiation to treat cancer
- Certain infections, especially those that inflame the heart
- Iron buildup in your heart muscle (hemochromatosis)
- A condition that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis)
- A disorder that causes the buildup of abnormal proteins (amyloidosis)
- Connective tissue disorders
Compared with a normal heart, dilated cardiomyopathy causes the chambers of the heart to enlarge, which can lead to heart failure if left untreated.
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.
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.
Hypertrophic cardiomyopathy. This type involves abnormal thickening of your heart muscle, particularly affecting the muscle of your heart's main pumping chamber (left ventricle). The thickened heart muscle can make it harder for the heart to work properly.
Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it becomes apparent during childhood. Most affected people have a family history of the disease, and some genetic mutations have been linked to hypertrophic cardiomyopathy.
Restrictive cardiomyopathy. In this type, the heart muscle becomes rigid and less elastic, 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 when iron builds up in the heart muscle (hemochromatosis).
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.
There are a number of factors 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 abuse
- Illicit drug use, such as cocaine, amphetamines and anabolic steroids
- Certain chemotherapy drugs and radiation therapy for cancer
- Certain diseases, such as diabetes, an under- or overactive thyroid gland, or a disorder that causes the body to store excess iron (hemochromatosis)
- Other conditions that affect the heart, such as a disorder that causes the buildup of abnormal proteins (amyloidosis), a disease that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis), or connective tissue disorders
Enlarged heart, in heart failure
As your heart weakens, such as in heart failure, it begins to enlarge, forcing your heart to work harder to pump blood to the rest of your body.
Cardiomyopathy can lead to other heart conditions, 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.
- Valve problems. Because cardiomyopathy causes the heart to enlarge, the heart valves might not close properly. This can lead to a backward flow of blood.
- Cardiac arrest and sudden death. Cardiomyopathy can lead to abnormal heart rhythms. These abnormal heart rhythms can result in fainting or, in some cases, sudden death if your heart stops beating effectively.
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 chance 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
Jan. 23, 2019