Cardiomyopathy is disease of the heart muscle that reduces the heart's ability to pump blood effectively. Different kinds of cardiomyopathy cause the heart muscle to enlarge, thicken, or become stiff. Cardiomyopathy can be due to a number of causes, including viral infections and certain medicines. It can also be inherited. Often, the exact cause of the muscle disease is never found. Cardiomyopathy can lead to irregular heart rhythms or heart failure.
Cardiomyopathy differs from many of the other disorders of the heart in several ways:
Cardiomyopathy can, and often does, occur in the young.
The condition tends to be progressive and sometimes worsens fairly quickly.
It may be associated with diseases involving other organs, as well as the heart.
Cardiomyopathy is a leading cause for heart transplants.
Cardiomyopathy prevents the heart muscle from pumping enough blood to meet the body's needs.
Viral infections that infect the heart are a major cause of cardiomyopathy. In some cases, cardiomyopathy is a result of another disease or its treatment, such as a complex congenital heart defect, nutritional deficiencies, very fast heart rhythms, or certain types of chemotherapy used for cancer. Sometimes, cardiomyopathy can be linked to a genetic problem. Other times, the cause is unknown. There are 4 types of cardiomyopathy that can affect both adults and children:
Arrhythmic right ventricular dysplasia (rare)
Dilated cardiomyopathy is the most common form of cardiomyopathy. The heart muscle becomes enlarged and stretched (dilated). This causes the heart to become weak and pump inefficiently. Problems that may occur with dilated cardiomyopathy include:
Irregular heart rhythms
Risk of blood clots
Leaky mitral valve
Various infections (including viral) which lead to inflammation of the heart muscle (myocarditis) can cause this type of cardiomyopathy.
Contact with toxins or very powerful therapeutic drugs, such as certain types of chemotherapy given to fight cancer, have been known to cause dilated cardiomyopathy. Heredity can also be a factor. About 20% of people with dilated cardiomyopathy have a parent or sibling with the disease. In many cases, a specific cause for this type of the disease is never found.
Because the heart muscle is weak and unable to pump enough blood to meet the body's demands, the body may try to preserve blood flow to essential organs such as the brain and kidneys by reducing blood flow to other areas of the body, such as the skin and muscles.
These are the most common symptoms of dilated cardiomyopathy:
Pale or ashen skin color
Cool, sweaty skin
Rapid heart rate
Rapid breathing rate
Shortness of breath
Your child's healthcare provider may recommend medicines to:
Help the heart beat more effectively
Decrease the workload of the heart
Decrease the oxygen requirements of the heart
Prevent blood clots from forming
Decrease inflammation of the heart
Regulate irregular heartbeats
In some cases, dilated cardiomyopathy due to viral causes improves over time. In other cases, the condition worsens and a heart transplant may be considered. Talk to your child's healthcare provider for more information about his or her specific outlook.
In hypertrophic cardiomyopathy, the muscle of the heart becomes thicker than normal, obstructing blood flow to the rest of the body.
The thickened muscle can also affect the mitral valve, which separates the left atrium and the left ventricle. The valve becomes leaky, allowing blood to move backwards from the left ventricle into the left atrium, instead of forward to the rest of the body.
Hypertrophic cardiomyopathy is often inherited. About one-half of children with the disease have a parent or sibling with varying degrees of left ventricular muscle or ventricular wall enlargement, although relatives may or may not have symptoms.
Children with hypertrophic cardiomyopathy may have symptoms that increase with exertion or symptoms may be unpredictable.
These are the most common symptoms of hypertrophic cardiomyopathy:
Shortness of breath on exertion
Abnormal heart rhythms
Your child's healthcare provider may recommend medicine to:
Surgical treatment may include:
Removal of part of the enlarged muscle
Implantation of a pacemaker or defibrillator
Talk to your child's healthcare provider for more information about his or her specific outlook.
Restrictive cardiomyopathy, the least common type of cardiomyopathy in the U.S., occurs when the myocardium of the ventricles becomes excessively stiff. When this happens, the ventricles are not able to relax to fill with blood between heartbeats. This condition occurs rarely in children.
Restrictive cardiomyopathy usually results from an underlying condition that affects the rest of the body. However, in some cases the cause is unknown (idiopathic). Restrictive cardiomyopathy does not appear to be inherited, but some of the diseases that lead to the condition may be genetic.
Conditions that may be associated with the development of restrictive cardiomyopathy include:
Scleroderma (a chronic, degenerative disease that affects the joints, skin, and internal organs)
Amyloidosis (a rare disease which causes the buildup of amyloid, a protein and starch, in tissues and organs)
Sarcoidosis (a rare inflammation of the lymph nodes and other tissues throughout the body)
Mucopolysaccharidosis (a condition in which mucopolysaccharides, or carbohydrates that bond with water to form a thick, jelly-like substance, accumulate in body organs)
Radiation therapy for cancer treatment has also been associated with restrictive cardiomyopathy.
These are the most common symptoms of restrictive cardiomyopathy:
Swelling of the extremities
Pacemaker or defibrillator insertion
ARVD is a rare type of cardiomyopathy that occurs if the muscle tissue in the right ventricle is infiltrated by scar tissue:
This process disrupts the heart's electrical system causing arrhythmias.
It usually affects teens and young adults.
Symptoms include heart palpitations and fainting after physical activity.
It can cause sudden cardiac arrest in young athletes.