Cardiomyopathies
Cardiomyopathy refers to diseases of the heart muscle. These diseases have a variety of causes, symptoms, and treatments.

In cardiomyopathy, the heart muscle becomes enlarged, thick, or rigid. In rare cases, the muscle tissue in the heart is replaced with scar tissue.

As cardiomyopathy worsens, the heart becomes weaker. It's less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to heart failure or arrhythmia. In turn, heart failure can cause fluid to build up in the lungs, ankles, feet, legs, or abdomen.

The weakening of the heart also can cause other severe complications, such as heart valve problems.

Overview
The four main types of cardiomyopathy are:

Dilated cardiomyopathy
Hypertrophic cardiomyopathy
Restrictive cardiomyopathy
Arrhythmogenic right ventricular dysplasia (ARVD)
The different types of the disease have different causes, signs and symptoms, and outcomes.

Cardiomyopathy can be acquired or inherited. "Acquired" means you aren't born with the disease but you develop it due to another disease, condition, or factor. "Inherited" means your parents passed the gene for the disease on to you. In many cases, the cause of cardiomyopathy isn't known.

Cardiomyopathy can affect people of all ages. However, certain age groups are more likely to have certain types of cardiomyopathy. This document focuses on cardiomyopathy in adults.

Outlook
Some people who have cardiomyopathy have no signs or symptoms and need no treatment. For other people, the disease develops rapidly, symptoms are severe, and serious complications occur.

Treatments for cardiomyopathy include lifestyle changes, medicines, surgery, implanted devices to correct arrhythmias, and a nonsurgical procedure. These treatments can control symptoms, reduce complications, and stop the disease from getting worse.

Types of Cardiomyopathy
 

Dilated Cardiomyopathy
Dilated cardiomyopathy is the most common type of the disease. It mostly occurs in adults aged 20 to 60. Men are more likely than women to have this type of cardiomyopathy.

Dilated cardiomyopathy affects the heart's ventricles and atria. These are the lower and upper chambers of the heart, respectively.

The disease often starts in the left ventricle, the heart's main pumping chamber. The heart muscle begins to dilate (stretch and become thinner). This causes the inside of the chamber to enlarge. The problem often spreads to the right ventricle and then to the atria as the disease gets worse.

When the chambers dilate, the heart muscle doesn't contract normally. Also, the heart can't pump blood very well. Over time, the heart becomes weaker and heart failure can occur. Symptoms of heart failure include fatigue (tiredness); swelling of the ankles, feet, legs, and abdomen; and shortness of breath.

Dilated cardiomyopathy also can lead to heart valve problems, arrhythmias, and blood clots in the heart.

Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy is very common and can affect people of any age. About 1 out of every 500 people has this type of cardiomyopathy. It affects men and women equally. Hypertrophic cardiomyopathy is the most common cause of sudden cardiac arrest (SCA) in young people, including young athletes.

This type of cardiomyopathy occurs when the walls of the ventricles (usually the left ventricle) thicken. Despite this thickening, the ventricle size often remains normal.

Hypertrophic cardiomyopathy may block blood flow out of the ventricle. When this happens, the condition is called obstructive hypertrophic cardiomyopathy. In some cases, the septum thickens and bulges into the left ventricle. (The septum is the wall that divides the left and right sides of the heart.) In both cases, blood flow out of the left ventricle is blocked.

As a result of the blockage, the ventricle must work much harder to pump blood out to the body. Symptoms can include chest pain, dizziness, shortness of breath, or fainting.

Hypertrophic cardiomyopathy also can affect the heart's mitral valve, causing blood to leak backward through the valve.

Sometimes the thickened heart muscle doesn't block blood flow out of the left ventricle. This is called nonobstructive hypertrophic cardiomyopathy. The entire ventricle may become thicker, or the thickening may happen only at the bottom of the heart. The right ventricle also may be affected.

In both types (obstructive and nonobstructive), the thickened muscle makes the inside of the left ventricle smaller, so it holds less blood. The walls of the ventricle also may stiffen. As a result, the ventricle is less able to relax and fill with blood.

These changes cause increased blood pressure in the ventricles and the blood vessels of the lungs. Changes also occur to the cells in the damaged heart muscle. This may disrupt the heart's electrical signals and lead to arrhythmias.

Rarely, people who have hypertrophic cardiomyopathy have no signs or symptoms, and the condition doesn't affect their lives. Others have severe symptoms and complications, such as serious arrhythmias, an inability to exercise, or extreme fatigue with little physical activity.

Rarely, people who have this type of cardiomyopathy can have SCA during very vigorous physical activity. The physical activity can trigger dangerous arrhythmias. If you have this type of cardiomyopathy, talk to your doctor about what types and amounts of physical activity are safe for you.

Restrictive Cardiomyopathy
Restrictive cardiomyopathy tends to mostly affect older adults. In this type of the disease, the ventricles become stiff and rigid. This is due to abnormal tissue, such as scar tissue, replacing the normal heart muscle.

As a result, the ventricles can't relax normally and fill with blood, and the atria become enlarged. Over time, blood flow in the heart is reduced. This can lead to problems such as heart failure or arrhythmias.

Arrhythmogenic Right Ventricular Dysplasia
Arrhythmogenic right ventricular dysplasia (ARVD) is a rare type of cardiomyopathy. ARVD occurs when the muscle tissue in the right ventricle dies and is replaced with scar tissue.

This process disrupts the heart's electrical signals and causes arrhythmias. Symptoms include palpitations and fainting after physical activity.

ARVD usually affects teens or young adults. It can cause SCA in young athletes. Fortunately, such deaths are rare.

Other Names for Cardiomyopathy
Alcoholic cardiomyopathy. This term is used when overuse of alcohol causes the disease.
Congestive cardiomyopathy.
Diabetic cardiomyopathy.
Familial dilated cardiomyopathy.
Idiopathic cardiomyopathy.
Ischemic cardiomyopathy. This term is used when coronary artery disease or heart attack causes the disease.
Peripartum cardiomyopathy. This term is used when the disease develops in a woman shortly before or after she gives birth.
Primary cardiomyopathy.
Other names for Hypertrophic Cardiomyopathy
Asymmetric septal hypertrophy
Familial hypertrophic cardiomyopathy
Hypertrophic nonobstructive cardiomyopathy
Hypertrophic obstructive cardiomyopathy
Idiopathic hypertrophic subaortic stenosis
Other names for Restrictive Cardiomyopathy
Infiltrative cardiomyopathy
Other names for Arrhythmogenic Right Ventricular Dysplasia
Arrhythmogenic right ventricular cardiomyopathy
Right ventricular cardiomyopathy
Right ventricular dysplasia
What causes Cardiomyopathy?
Cardiomyopathy can be acquired or inherited. "Acquired" means you aren't born with the disease, but you develop it due to another disease, condition, or factor.

"Inherited" means your parents passed the gene for the disease on to you. Researchers continue to look for the genetic links to cardiomyopathy. They also continue to explore how these links cause or contribute to the various types of cardiomyopathy.

Many times, the cause of cardiomyopathy isn't known. This is often the case when the disease occurs in children.

Dilated Cardiomyopathy
In more than half of the cases of dilated cardiomyopathy, the cause isn't known. As many as one-third of the people who have dilated cardiomyopathy inherit it from their parents.

Certain diseases, conditions, and substances also can cause the disease, such as:

Coronary artery disease, heart attack, diabetes, thyroid disease, viral hepatitis, and HIV
Infections, especially viral infections that inflame the heart muscle
Alcohol, especially if you also have a poor diet
Complications during the last month of pregnancy or within 5 months of birth
Certain toxins, such as cobalt
Certain drugs (such as cocaine and amphetamines) and two medicines used to treat cancer (doxorubicin and daunorubicin)
Hypertrophic Cardiomyopathy
Most cases of hypertrophic cardiomyopathy are inherited. It also can develop over time because of high blood pressure or aging.

Sometimes, other diseases, such as diabetes or thyroid disease, can cause hypertrophic cardiomyopathy. Sometimes the cause of hypertrophic cardiomyopathy isn't known.

Restrictive Cardiomyopathy
Certain diseases and conditions can cause restrictive cardiomyopathy, including:

Hemochromatosis. This is a disease in which too much iron builds up in your body. The extra iron is toxic to the body and can damage the organs, including the heart.
Sarcoidosis. This is a disease that causes inflammation (swelling). It can affect various organs in the body. The swelling is due to an abnormal immune response. This abnormal response causes tiny lumps of cells to form in the body's organs, including the heart.
Amyloidosis. This is a disease in which abnormal proteins build up in the body's organs, including the heart.
Connective tissue disorders.
Arrhythmogenic Right Ventricular Dysplasia
Researchers think that arrhythmogenic right ventricular dysplasia is an inherited disease.

Who is at risk for Cardiomyopathy?
People of all ages can have cardiomyopathy. However, certain types of the disease are more common in certain groups.

Dilated cardiomyopathy is more common in African Americans than in Whites. This type of the disease also is more common in men than women.

Teens and young adults are more likely than older people to have arrhythmogenic right ventricular dysplasia, although it's rare in both groups.

Major risk factors
Certain diseases, conditions, or factors can raise your risk for cardiomyopathy. Major risk factors include:

A family history of cardiomyopathy, heart failure, or sudden cardiac arrest (SCA)
A disease or condition that can lead to cardiomyopathy, such as coronary artery disease, heart attack, or a viral infection that inflames the heart muscle
Diabetes, other metabolic diseases, or severe obesity
Diseases that can damage the heart, such as hemochromatosis, sarcoidosis, or amyloidosis
Long-term alcoholism
Long-term high blood pressure
Some people who have cardiomyopathy never have signs or symptoms. That's why it's important to identify people who may be at high risk for the disease. This can help prevent future problems, such as serious arrhythmias or SCA.

What are the signs and symptoms of Cardiomyopathy?
Some people who have cardiomyopathy never have signs or symptoms. Others don't have signs or symptoms in the early stages of the disease.

As cardiomyopathy worsens and the heart weakens, signs and symptoms of heart failure usually occur. These signs and symptoms include:

Shortness of breath or trouble breathing.
Fatigue (tiredness).
Swelling in the ankles, feet, legs, and abdomen. Rarely, swelling may occur in the veins of your neck.
Other signs and symptoms can include dizziness, lightheadedness, fainting during physical activity, chest pain, arrhythmias, and heart murmur (an extra or unusual sound heard during a heartbeat).

How is Cardiomyopathy diagnosed?
Your doctor will diagnose cardiomyopathy based on your medical history, a physical exam, and the results from tests and procedures.

Specialists involved
Often, a cardiologist or pediatric cardiologist diagnoses and treats cardiomyopathy. A cardiologist is a doctor who specializes in treating heart diseases. A pediatric cardiologist is a doctor who specializes in treating heart diseases in children.

Medical history
Your doctor will want to learn about your medical history. He or she will want to know what symptoms you have and how long you've had them. Your doctor also will want to know whether anyone in your family has had cardiomyopathy, heart failure, or sudden cardiac arrest.

Physical exam
Your doctor will use a stethoscope to listen to your heart and lungs for sounds that may suggest cardiomyopathy. These sounds may even suggest a certain type of the disease.

For example, the loudness, timing, and location of a heart murmur may suggest hypertrophic obstructive cardiomyopathy. A "crackling" sound in the lungs may be a sign of heart failure. (This condition often develops in the later stages of cardiomyopathy.)

Physical signs also help your doctor diagnose cardiomyopathy. Swelling of the ankles, feet, legs, or abdomen suggests fluid buildup, a sign of heart failure.

Signs or symptoms of cardiomyopathy may be found during a routine exam. For example, your doctor may hear a heart murmur or you may have abnormal test results.

Diagnostic tests
You may have one or more of the following tests to diagnose cardiomyopathy.

Blood tests: During a blood test, a small amount of blood is taken from your body. It's usually drawn from a vein in your arm using a thin needle. The procedure usually is quick and easy, although it may cause some short-term discomfort.

Blood tests give your doctor information about your heart and help rule out other conditions.