Understanding Pediatric Cardiomyopathy


What is pediatric cardiomyopathy?

Cardiomyopathy means “a disease of the heart muscle.” It is a chronic and sometimes progressive disease in which the heart muscle (myocardium) becomes abnormally enlarged, thickened and/or stiffened such that the heart can no longer contract or relax normally. Eventually, the heart loses its ability to pump blood effectively and irregular heartbeats (arrhythmias) and heart failure may occur.

Cardiomyopathy can affect anyone regardless of age, race, gender or socioeconomic background. While cardiomyopathy predominantly affects adults, in rare instances it does affect infants and children, in which case it is called pediatric cardiomyopathy.

Cardiomyopathy is the leading reason for heart transplants and sudden deaths in children. It is estimated that at least 100,000 children worldwide are affected with cardiomyopathy. According to the Pediatric Cardiomyopathy Registry, 1 in every 100,000 children in the U.S. under the age of 18 is diagnosed with cardiomyopathy. The majority of diagnosed children are under the age of 12 months, followed by children 12 to 18 years of age.

There are four types of cardiomyopathy:

Dilated Cardiomyopathy (DCM)
The most common form, this occurs when the muscle fibers of one or both pumping chambers are weak and unable to contract normally. As the heart pumps less strongly, it enlarges to help deliver more blood with each beat. Eventually the weakened heart fails, causing fluid to build up in other organs.

Hypertrophic Cardiomyopathy (HCM)
The second most common form is characterized by the abnormal growth and arrangement of muscle fibers in the heart. The thickened and stiffer heart muscles reduce the capacity of the heart to fill and contract properly. It may also lead to arrhythmias or narrowing of the passage out of the heart. In advanced HCM, the heart muscle may thin and stretch to compensate for the poor pumping action.

Restrictive Cardiomyopathy (RCM)
A less common condition, it accounts for 3-5% of patients with cardiomyopathy. With this form, the heart has normal contraction but abnormal relaxation. The walls of the ventricles become stiff, preventing the heart from filling with blood. The low amount of blood in the heart leads to exercise intolerance and heart failure.

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
The least common type and extremely rare in young children, this condition usually presents in teens or young adults. ARVC is caused by the death of healthy heart muscle and its replacement with scar tissue and fat. This results in a disorganized structure of heart muscle tissues causing abnormal electrical activities (arrhythmia) and problems with the heart’s contraction.

There are also new forms of cardiomyopathy that are being recognized. Left ventricular non-compaction cardiomyopathy (LVNC) is a rare form of cardiomyopathy that can manifest as DCM or RCM. With this condition, the developing heart muscle fails to become compacted, resulting in a spongiform appearance of the chamber wall, increased muscle thickness and weak pumping action.

Each type of cardiomyopathy is characterized by a slightly different disease process and set of symptoms. For specific information on the different forms of cardiomyopathy, please refer to the inserts available with this booklet.

 

What causes cardiomyopathy?

The cause of cardiomyopathy in children is currently poorly understood. In approximately two-thirds of reported cases, the cause of pediatric cardiomyopathy has not been identified. According to the Pediatric Cardiomyopathy Registry, of the cases with known causes, myocarditis (27%) and familial inheritance (25%) are the leading causes of cardiomyopathy in children. These are followed by neuromuscular disorders (22%), metabolic disorders (16%) and genetic malformation syndromes (10%).

The cause of cardiomyopathy can be genetic or acquired. Some cardiomyopathies are isolated affecting only the heart with either unknown (idiopathic) or genetic causes. Cardiomyopathy can also be associated with other medical problems that have an unknown or genetic cause. Genetic conditions are usually caused by changes in specific genes (mutations) that are inherited from one or both parents. In some instances, cardiomyopathy can occur for the first time in a family due to a sporadic genetic mutation in the child. Inherited causes of cardiomyopathy can be passed on from one or both parents. For example, with autosomal dominant genetic conditions, one parent carries a genetic mutation for cardiomyopathy and has a 50% chance of passing it on to a son or daughter. Usually this parent also has cardiomyopathy but may or may not show symptoms of the disease.

With autosomal recessive genetic conditions such as fatty acid oxidation defects or glycogen storage diseases in which cardiomyopathy is a common symptom, both parents are unaffected carriers and have a 25% chance of having a child with cardiomyopathy. Some forms of cardiomyopathy caused by Barth syndrome or Duchene muscular dystrophy can occur sporadically in boys or may be passed on from mother to son (X-linked transmission). In the latter, sons will be at a 50% risk of having the condition while daughters will not have the condition but may be carriers like their mothers.

Some cardiomyopathies are acquired due to exposures to infection, toxin or medication, which can weaken the heart muscle. The most common cause of acquired cardiomyopathy is myocarditis, a viral infection that causes inflammation of the heart. Viruses that can affect the heart include Coxsackie A & B, Echovirus, Adenovirus, HIV and Mumps. Less common causes of acquired cardiomyopathy include exposure to excessive alcohol, radiation, heavy metals, cancer chemotherapy drugs and nutritional deficiencies.

Cardiomyopathy can also develop in response to an underlying medical condition that affects other organs or the entire body system. These include metabolic and mitochondrial abnormalities, build up of proteins in the heart (amyloidosis), excess iron in the heart (hemochromatosis), thyroid disorders, severe anemia, complications from other cardiovascular conditions (congenital heart defect, hypertension or surgery), autoimmune diseases (lupus) and pregnancy related complications.

There are over 100 specific causes of cardiomyopathy in children that can be classified into one of the four types (DCM, HCM, RCM and ARVC). Determining the root cause of the disease can be a complex and involved process. Most of the rare disorders associated with cardiomyopathy can only be confirmed by diagnostic testing and evaluation from other medical specialists. Your child’s pediatric cardiologist and team of specialists (geneticists and neurologists) will work together to discover the origin of the disease in your child.

How is cardiomyopathy diagnosed?

Since pediatric cardiomyopathy is rare and most often of unknown origin (idiopathic), a diagnosis can be elusive. Many times the disease goes undetected in young children because there is no family history of cardiomyopathy or the child shows no symptoms (asymptomatic). Many children with cardiomyopathy are active, appear healthy and meet their developmental milestones.

An accurate and thorough diagnosis involves determining the type of cardiomyopathy, its severity and cause. The more specific the diagnosis, the more tailored and effective the treatment can be. If a child is suspected of having cardiomyopathy, an evaluation will begin with a visit to a pediatric cardiologist for a complete history review and physical examination. During the evaluation, the physician will ask about the child's and family’s medical history, symptoms and prior medical tests. The physician will also examine the child and listen to the heart through a stethoscope. Specific cardiac tests will follow to determine the heart size and whether there is thickening, obstruction of blood flow or valve leakage.

Diagnosis is confirmed by an electrocardiogram (EKG) and two-dimensional echocardiogram with Doppler ultrasound. An EKG records the heart’s electrical activity (rate and rhythm) using electrodes placed on the child’s arms, legs and chest wall.

An echocardiogram uses ultrasound waves to produce moving pictures of the beating heart on a video screen. These cross-sectional views of the heart allow the cardiologist to measure the heart’s size, muscle thickness, pumping ability, degree of obstruction and potential leakage (regurgitation). Other noninvasive procedures that do not penetrate the skin may be performed, including magnetic resonance imaging (MRI), a Holter monitor and an exercise stress test for older children. In some cases, an invasive procedure under anesthesia may be necessary to further investigate the heart function or to determine possible causes. This includes cardiac catheterization, radionuclide ventriculogram, endomyocardial biopsy (heart biopsy), muscle biopsy or an electrophysiology (EP) study. These procedures are explained in more detail on CCF’s website.

If necessary, the diagnostic visit may also involve blood or urine testing, assessment of a child’s neurological development and muscle tone, review of any unusual physical features associated with related syndromes and evaluation of other organs that might be affected. Some forms of cardiomyopathy are further defined by genetic testing.

During the evaluation process, you may work with a pediatric cardiologist, geneticist, heart surgeon and possibly specialists from neurology, immunology, nutrition, endocrinology and infectious disease. Whenever possible, it is best to work with a team of experts at a medical center that treats many children with cardiomyopathy and engages in research on the disease. These are usually large teaching hospitals with a heart failure/heart transplant program and/or a pediatric cardiomyopathy clinic.

 

What are the common symptoms?

Cardiomyopathy is an extremely variable disease in which the physical characteristics of the heart muscle and resulting symptoms vary greatly. Symptoms can be absent, mild or severe. Assessing the severity of the disease based on symptoms can be complicated by the inability of babies and young children to communicate how they feel.

Children may be diagnosed following the detection of a heart murmur or evidence of heart enlargement during a routine visit to the pediatrician. However, it may not always be so obvious and often the early signs of cardiomyopathy can be confused with a common cold, flu, asthma or stomachache. Because cardiomyopathy is not easily detected during a physical examination, many children are only diagnosed in the later stages of the disease once a child exhibits more serious symptoms. Shortness of breath, rapid breathing, fainting spells, irregular or very rapid heart rate, chest pain and extreme fatigue are all symptoms that warrant an evaluation by a heart specialist. In infants, poor weight gain, difficulty feeding, excessive sweating and unusual fussiness or lethargy are all symptoms to watch for.

Because symptoms can vary with different types of cardiomyopathy and among family members with the same form of cardiomyopathy, it is best to consult with a pediatric cardiologist if you have concerns about symptoms in your child. For more information on the specific symptoms associated with each type of cardiomyopathy, please see the inserts available with this booklet.

What are available treatment options?

The aim of treatment is to restore a child to the best health possible with the least amount of intervention. Since each type of cardiomyopathy has a varying course, each child will require an individualized treatment plan. Factors that will determine the appropriate therapy include the child’s age, overall health, medical history, underlying cause of the disease, stage of the disease and the child’s tolerance for specific medications, procedures or therapies and expectations for the course of the disease. A child's medical management should be done in consultation with a pediatric cardiologist, and a cardiothoracic surgeon, electrophysiologist and geneticist, if needed.

Currently there is no cure that can repair the structural damage of the heart muscle and guarantee long-term survival, but accurate diagnosis and early intervention can improve outcomes. The body can heal some forms of cardiomyopathy and medical support can facilitate this healing process. There are also specific therapies for some of the rare forms of cardiomyopathy. The goal of medical therapy, therefore, is to prevent the disease from progressing, improve the function of a failing heart, control symptoms related to heart failure or heart obstruction and prevent complications such as blood clots and arrhythmias. Each type of cardiomyopathy requires slightly different short and long-term medical management of the disease.

If detected at an early stage, cardiomyopathy can be controlled with long-term drug therapy, placement of a pacemaker/defibrillator or surgery. Drug therapy is used to help the heart beat more effectively, decrease the heart’s workload and oxygen requirement, prevent clots from forming, decrease inflammation of the heart and regulate abnormal heart rhythms. Drugs commonly used to manage cardiomyopathy include angiotensin converting enzyme (ACE) inhibitors, beta-blockers, calcium-channel blockers, digoxin, diuretics, anti-arrhythmic, antibiotics and anti-coagulants. The combination of drugs and dosages are prescribed according to each child’s individual condition and may change as a child grows and/or responds to a medication. While drug therapy is non-invasive, it can have side effects and therefore requires careful monitoring.

If a child has an arrhythmia that needs to be controlled, a pacemaker or automatic implantable cardioverter defibrillator (AICD) may be prescribed. This is a small mechanical device surgically placed under the skin of the chest or abdomen with wire leads threaded through veins into the heart or attached to the surface of the heart. This is a self-regulating sensing device that activates when a patient’s heartbeat reaches dangerously high or low levels. In some cases of DCM, a biventricular pacemaker may be used to synchronize the contraction of the left and right chambers of the heart, even if no arrhythmia is present.

Surgery may be an additional treatment for patients with HCM. Septal myectomy (resection of the thickened heart muscle) and valve replacement are used primarily to control heart failure symptoms but do not stop the disease from progressing. For DCM and RCM, there are no surgical options for improving heart failure. When a child no longer responds to treatment and experiences end-stage heart failure, a heart transplant may be necessary. While waiting for a donor heart, intravenous medications and cardiac assist devices (mechanical hearts) may be used to extend the life of a child’s heart.

What is the likely prognosis for my child?

The long-term outlook for pediatric cardiomyopathy continues to be unpredictable. Depending on the type of cardiomyopathy, cause of the disease and stage at which the child is diagnosed, the outcome may vary greatly. Even if a child has a family history of the disease, the degree to which he or she is affected can differ considerably from his/her parents or siblings. Some children will stabilize with proper treatment and are able to lead relatively normal lives with minor exercise restrictions. Other children with more complex forms of cardiomyopathy may face more limitations, need specialized care or encounter minor developmental delays. Occasionally, children with certain types of cardiomyopathy do improve with proper treatment but most do not show full recovery of heart function.

For the more severe cases, a heart transplant may be the only treatment option. Approximately 20% of infants and children with symptomatic DCM require a heart transplant within two years of diagnosis. In children with HCM, transplantation is less common. Survival after transplantation is good with a one and two-year survival rate of approximately 80%. Long-term survival remains to be determined but is expected to improve with more medical progress.

 

Should my family undergo screening or genetic testing?

Since cardiomyopathy can be inherited, other family members may be at risk even if they have no symptoms. Therefore, it is recommended that parents and siblings of a diagnosed child undergo an echocardiogram and EKG screening. This is especially the case if there is a family history of sudden infant death, sudden cardiac arrest or heart attack at less than 40 years of age. Even if the initial exam results are normal, family members may need periodic re-screening. Screening frequency will depend on the type of cardiomyopathy, its cause and the age of the individual. Your cardiologist and geneticist will advise what is appropriate for your family’s medical situation.

Clinical genetic testing of blood or tissue may also be an option for certain types of cardiomyopathy. These tests determine whether an individual has a particular genetic mutation that may cause the disease. Early detection can lead to treatment and intervention that can control or limit the damage caused by the disease. Parents discovered to carry a gene causing cardiomyopathy should seek genetic counseling to determine who else in the extended family may be at risk and to discuss the possibility of recurrence in future pregnancies.

 

How will the disease impact my child and family?

While pediatric cardiomyopathy is a potentially serious condition, many children can lead a normal life with proper medical management. The degree of impact on lifestyle will depend on whether a child improves, stabilizes or progresses to an advanced stage of heart failure. It will also depend on the type of cardiomyopathy and its cause. A diagnosis will mean more frequent physician visits to monitor the heart’s function and assess the treatment plan. It may also mean daily intake of various medications and possibly surgical procedures. If there are complications from the disease leading to prolonged hospitalization, a child may temporarily fall behind developmentally or academically.

Daily challenges that might arise include dealing with the psychological issues of living with the disease and adjusting to modified routines such as the frequency of medical super-vision, medication intake, diet and the amount of activity. Besides these immediate changes, there may be other issues as a child gets older which may include handling school and social situations, accessing special child services, maintaining ongoing health and obtaining health or life insurance.

Poor appetite and slow weight gain are common in children with more severe cardiomyopathy. This can result from a child's inability to take in sufficient calories while the body is trying to compensate for the heart's increased workload. Poor appetite may also result from rapid breathing, fatigue, frequent respiratory infections and poor absorption of nutrients from the intestines. In these cases, a nutritionist may recommend smaller, more frequent feedings, a higher calorie diet or a caloric supplement to boost weight gain. With some forms of metabolic cardiomyopathy a low fat diet or special formulations are prescribed to correct the fundamental cause of the disease. In addition, children taking certain types of medication may require higher levels of magnesium or potassium in their diet, whereas children with DCM and heart failure may need a low sodium diet to prevent fluid retention.

Most young children with cardiomyopathy do not have any physical or mental limitations that would prevent them from participating in playgroups or school activities. Older children may need to limit gym activities that involve vigorous exertion. Whether or not a child has symptoms, medical experts generally recommend refraining from weight lifting, competitive team sports and strenuous activities because of the possibility of sudden collapse. Excessive sweating or exposure to extremely cold temperatures during exercise may also cause the heart to work harder and aggravate existing symptoms. On the other hand, moderate aerobic exercises, walking, light running and less intense recreational sports are acceptable as long as they do not lead to dehydration or exhaustion. Your child’s cardiologists should be consulted for activity restrictions specific to your child’s medical situation.

The school counselor, school nurse and physical education and classroom teachers should be made aware of your child's condition. Topics to discuss might include academic issues resulting from illness and fatigue, social issues resulting from being perceived as “different” and practical issues such as special dietary needs, common symptoms, medication side effects, implantable device precautions, exercise/sports restrictions and the need for external defibrillators and CPR-trained personnel on premise. An individualized education plan (IEP) can be developed to accommodate any special school needs. This may include a place and time to take medication, tutoring or test-taking modifications, adaptive physical education and special arrangements to reduce fatigue during the school day. The school nurse should also keep a list of your child’s medications and possible side effects, physician contact details, information on the signs of cardiac distress and a medical emergency plan.

There will also be other considerations, which include the need to get a medical alert bracelet or portable external defibrillator, adjustments to your child’s medication schedule due to travel or special activities and determining which family members should get CPR training. Other precautions include getting an annual flu shot to protect the heart from influenza, taking antibiotics before dental or surgical procedures to prevent bacterial infections of the heart (endocarditis) and avoiding over-the-counter decongestants and herbs that may accelerate the heart rate.

Finally, there will be a need to explain the disease to your child, his or her siblings and those close to your child. You can help siblings, friends and classmates understand and accept your child’s condition by explaining the disease in simple terms using age-appropriate books and role-play. Child life professionals and pediatric psychiatrists can also help address any specific concerns that your child has.

How do I cope with a chronic disease?

As with any chronic life-threatening disease, there are concerns and implications for the entire family. The possibility of deterioration or premature death creates unique social and emotional issues for families. The anxiety of an uncertain future combined with the isolation of dealing with a rare disorder can make raising a child with cardiomyopathy stressful at times. Some families feel responsible for passing the disease on to their child while others mourn the lost dream of raising a healthy child. As a parent, it is natural to feel a mixture of intense emotions such as fear, anger, guilt, shame and sadness. Keeping a journal, maintaining open communication with family members and developing a support network – whether it is relatives, friends, a faith-based group or other cardiomyopathy families – will help you to adapt and accept the challenges of living with the disease.

Being knowledgeable about the disease can also alleviate feelings of fear and helplessness. Educate yourself and your family about pediatric cardiomyopathy and be prepared for a cardiac emergency should it occur. Some parents may find themselves becoming overly protective but it is important to try to maintain a “normal” lifestyle and allow your child to interact with other children and engage in routine play. As long as your child is being monitored regularly and receiving appropriate treatment, the likelihood of a sudden cardiac event is low.

As your child gets older, he/she may face different social and emotional concerns related to the disease. While your child passes through these psychological stages, you should try to manage your own feelings so that your fears and disappointments do not interfere with your child's coping process or outlook on life. With many children, restrictions in activities can make them feel different or left out. Therefore, it is important to involve your child in activities that are less physically assertive, yet are rewarding and enjoyable. Be positive about what your child can do rather than focus on what he/she cannot do. Work together to find special-interest clubs and activities that may provide a sense of inclusion as well as build self-esteem.

You can help your child adjust by educating him/her about the disease and about what to expect. Encourage your child to become involved in his/her own care, to recognize his/her physical limitations and to be aware of certain warning signs that need medical attention. Your child should also feel comfortable talking about his/her condition with others. With this approach, your child will more likely be confident and positive about living with cardiomyopathy.

 

Where do I go for more information and support?

Cardiomyopathy is a complex disease and it can be difficult to understand completely. Healthcare professionals, support groups and other resources can provide you with information, encouragement and an outlet for expressing your concerns. The Children’s Cardiomyopathy Foundation (CCF) (www.childrenscardiomyopathy.org) provides detailed information on pediatric cardiomyopathy as well as helpful resources. Additional resources include the American Heart Association (www.americanheart.org), the National Organization for Rare Disease (www.rarediseases.org) and the National Heart, Lung and Blood Institute (www.nhlbi.org). For more specific answers to your questions you should contact your pediatric nurse, cardiologist or specialist.

Talking to families with similar circumstances can also be informative and comforting. Group support can be especially helpful at the beginning stages and on a long-term basis. The Children’s Cardiomyopathy Foundation (CCF) can help put you in touch with other affected families who understand the issues that you are facing. If there is no support group in your community specifically for pediatric cardiomyopathy, there may be other local or hospital-based groups with broader concerns such as chronically ill children or children with heart disorders.

What research is underway?

Most of the research to date has been focused on identifying the specific genes that cause cardiomyopathy and on understanding how these genetic abnormalities contribute to the disease. Some studies have been done on mouse models to mimic the disease found in humans and others are genetic studies of extended families with a strong history of cardiomyopathy. While researchers have identified certain genes responsible for different forms of cardiomyopathy, there are many more genes that have not been discovered. Researchers also continue to study why the disease manifests and progresses so differently among individuals with the same affected gene.

Basic research of this kind is necessary to advance medical understanding of the disease before any new therapies can be developed or tested on children. It also aids in developing comprehensive and affordable genetic tests. These types of diagnostic tests, run in a clinical laboratory, help to confirm diagnosis earlier, determine the outcome for existing and future children as well as anticipate future care and intervention for other family members.

Aside from molecular based research, the National Institute of Health (NIH) funded North America Pediatric Cardiomyopathy Registry (PCMR) is tracking, recording and analyzing clinical data on the features and outcomes of children with cardiomyopathy. In partnership with PCMR, CCF has established a Pediatric Cardiomyopathy Repository to collect DNA and tissue samples for researchers to study this disease. Multi-center studies focused on factors affecting disease progression and long-term outcome have also been initiated by the Pediatric Heart Network and Pediatric Heart Transplant Study Group.

Getting more families involved in research is important to advancing medical knowledge on pediatric cardiomyopathy. If your family is interested in participating in research, your child’s pediatric cardiologist and geneticist can guide you in selecting the most appropriate studies.

What else should I keep in mind?

It is important to remember that cardiomyopathy in children is rare. Therefore, information on the disease is limited and knowledge in the field is still evolving. When reviewing published medical literature on the disease, a parent should keep in mind that the study may be based on the most serious cases and that there is a wide spectrum of outcomes.

With any rare condition such as pediatric cardiomyopathy, parents/caregivers need to take an active role in their child’s disease management. Try to learn as much as possible about your child’s disease so that you can make informed decisions. Prior to any appointment, prepare a list of questions to discuss all relevant concerns. Remember that no question is too simple or unimportant to ask. Also, work closely with your child’s medical team to provide feedback that might assist in the evaluation.

When necessary, do not be afraid to seek a second opinion or to ask your physician to consult with a cardiomyopathy/heart failure center. Specialists at these medical centers will likely have more experience managing children with cardiomyopathy and be aware of the latest treatment developments. These specialty centers will also have expertise in arrhythmia, heart failure, cardiac assist devices and transplantation. Educating yourself about the disease, taking a proactive approach and consulting with the top specialists will ensure that your child gets the best possible medical care.

The information provided in this booklet is meant to assist families and caregivers by providing a broad overview of the disease. The material presented is not intended to be complete or to replace the advice given by a medical professional. Only a physician can offer guidelines on treatment options and lifestyle restrictions that are right for your child.

 

What is the Children’s Cardiomyopathy Foundation?

The Children’s Cardiomyopathy Foundation (CCF) is a national non-profit organization dedicated to saving lives and improving the quality of life for those affected by pediatric cardiomyopathy. Founded in 2002 by a parent who lost two young children to the disease, CCF’s mission is to accelerate the search for a cure by stimulating and funding promising research on pediatric cardiomyopathy, by educating and assisting physicians and patients on the complexities of the disease, and by increasing awareness and advocacy related to the needs of affected children and their families.

As the only public interest group focused on cardiomyopathy in children, CCF actively works with federal, private and corporate organizations to advance research and medical knowledge on this heart condition. Guided by a medical advisory board, CCF also provides information and support to 1,800 healthcare professionals and close to 300 families worldwide. The hope is that one day pediatric cardiomyopathy can be prevented and any affected child can be cured to live a full and productive life.

Register with CCF:
www.childrenscardiomyopathy.org

Contact Information:

Children’s Cardiomyopathy Foundation

P.O. Box 547 | Tenafly, New Jersey 07670
Tel: 201-227-8852 | Fax: 201-227-7016
Toll Free: 866-808-CURE (2873)
E-Mail

Funded in part by a grant from the
Medtronic Foundation and eBay Foundation.

Strategy and design provided by
Healthcare Branding Group, Inc.

© Copyright 2006 Children’s Cardiomyopathy Foundation