Cardiomyopathy is disease of the heart muscle. It makes it harder for the heart to pump blood. There are different types of the disease. Each of these can cause the heart muscle to get larger, thicken, or become stiff. Cardiomyopathy keeps the heart muscle from pumping enough blood to meet the body's needs.
There are four types of cardiomyopathy that can affect both adults and children:
Dilated cardiomyopathy (DCM)
Hypertrophic cardiomyopathy (HCM)
Restrictive cardiomyopathy (RCM)
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Cardiomyopathy differs from many other heart problems in several ways:
It can affect children.
It tends to get worse.
It may be linked to diseases of organs besides the heart.
It's a leading cause of the need for heart transplants.
Cardiomyopathy can have a number of causes. These include:
High blood pressure
Heart rhythm problems
Congenital heart defects
Often, the exact cause is never found. This is called idiopathic. Cardiomyopathy can lead to heart rhythm problems (arrhythmias) or heart failure.
Viral infections in the heart are a common cause of cardiomyopathy. In some cases, it's a result of another disease or its treatment. For example, it might be caused by a heart problem a child is born with (congenital). Or it might be caused by nutrition problems, very fast heart rhythms, or certain types of chemotherapy. Cardiomyopathy can sometimes be linked to a gene change. But the exact cause is often unknown.
DCM is the most common form of cardiomyopathy. The heart muscle becomes enlarged and stretched (dilated). This causes the heart to become weak. It can't pump well. Problems that may occur with DCM include:
Heart valve disease
Infections lead to inflammation of the heart muscle (myocarditis). The infections are often from viruses. This is one of the most commonly found causes of DCM. Many other cases are likely inherited. About 2 in 5 to 3 in 10 children with DCM have a relative with the disease.
DCM can also be caused by having contact with toxins or very strong medicines, such as some types of chemo. Genes can also play a role. About 1 in 5 people with DCM have a parent or sibling with the disease. In many cases, the cause for this type of the disease isn't found.
When the heart muscle is weak and can't pump enough blood to meet the body's demands, the body may try to reduce blood flow to some areas of the body. This keeps blood flow to vital organs, such as the brain and kidneys. Areas that may get less blood include the skin and muscles.
These are the most common symptoms of DCM:
Pale or gray skin color
Cool, sweaty skin
Rapid heart rate
Rapid breathing rate
Shortness of breath, especially when lying down
Loss of appetite
Your child's healthcare provider may recommend medicines to:
Help the heart beat better
Decrease the workload of the heart
Decrease the oxygen needs of the heart
Prevent blood clots
Decrease inflammation of the heart
Control heartbeat problems
In some cases, DCM caused by a virus gets better over time. In other cases, the condition gets worse. Your child may need a heart transplant. Talk with your child's provider for more information about your child's case.
In HCM, the muscle of the heart becomes thicker than normal. This blocks some blood flow to the rest of the body.
The thickened muscle may also affect the mitral valve. This valve separates the left atrium and the left ventricle. The valve may become leaky. This lets blood flow backwards from the left ventricle into the left atrium, instead of forward to the rest of the body.
HCM is often inherited. About half of children with the disease have a parent or sibling with some thickening of the left ventricular muscle or ventricular wall. These relatives may or may not have symptoms.
Children with HCM may have symptoms that get worse with exertion. But symptoms may often be hard to predict.
These are the most common symptoms of HCM:
Shortness of breath with exertion
Abnormal heart rhythms
Your child's healthcare provider may recommend medicine to:
Control irregular heartbeats
Surgery may include:
Removing part of the enlarged muscle
Inserting a pacemaker or defibrillator
Talk with your child's provider for more information about your child's case.
RCM is an uncommon type of cardiomyopathy in the U.S. It occurs when the heart muscle of the ventricles becomes too stiff. Then the ventricles don't relax to fill with blood between heartbeats. This condition rarely occurs in children.
RCM is often caused by a condition that affects the rest of the body. But in some cases the cause is unknown (idiopathic). RCM doesn't appear to be inherited. But some of the diseases that lead to the condition may be genetic.
Health conditions that may be linked with RCM include:
Scleroderma, a chronic, degenerative disease that affects the joints, skin, and internal organs
Amyloidosis, a rare disease that causes the buildup of a protein called amyloid in tissues and organs
Sarcoidosis, a rare inflammation of the lymph nodes and other tissues throughout the body
Mucopolysaccharidosis, a condition in which carbohydrates that bond with water to form a thick, jelly-like substance (mucopolysaccharides) build up in body organs
Radiation therapy for cancer treatment has also been linked with RCM.
These are the most common symptoms of RCM:
Swelling of the arms or legs
ARVC is a rare type of inherited cardiomyopathy. It occurs if the muscle tissue in the right ventricle has scar tissue. The scar tissue disrupts the heart's electrical system. This causes arrhythmias. ARVC usually affects teens and young adults. Symptoms include heart palpitations and fainting after physical activity. It can cause sudden cardiac arrest in young athletes.
Treatment often includes:
Medicines that slow the heart rate and treat symptoms of heart failure
Inserting a defibrillator
Heart transplant (in severe cases)