Cardiomyopathy

In this kind, the heart muscle is weakened, and the heart becomes enlarged and stretched. As the heart works harder to try keeping up with the body’s needs, it can get bigger and become weaker over time. This is the most common kind of cardiomyopathy in children.

There are several causes:

• Certain infections (usually viral) can irritate the heart muscle (a condition called myocarditis) and weaken it. In many cases, the infection can be treated and the heart muscle can recover, but sometimes the damage is permanent.
• Sometimes children born with other heart conditions develop dilated cardiomyopathy. This can happen because of the heart condition or surgeries they have had or because the heart muscle gets tired and weak over time.
• Some medicines can injure the heart muscle. One example is chemotherapy for cancer.
• Some kinds of arrhythmias – if they go on for a long time – can cause the heart muscle to become weak.
• Some forms of dilated cardiomyopathy are genetic, meaning the disease can be passed down from parents to children in their genes. Genetic cardiomyopathies often run in families.

Sometimes, doctors cannot find a cause. They call this idiopathic dilated cardiomyopathy.

In this kind, the heart muscle is too thick. This can cause problems in how the heart relaxes and fills with blood, how it pumps blood out to the body or both. Hypertrophic cardiomyopathy can also cause abnormal heart rhythms.

Usually, this kind of cardiomyopathy is caused by a problem with genes that affect how the heart muscle develops. Some babies born with this condition show signs at birth. But in many people, it is not diagnosed until later in life. Hypertrophic cardiomyopathy can also happen after birth because of another health problem, such as a hormone problem that causes excess growth (acromegaly).

In this kind, the heart muscle becomes very stiff, making it harder for the ventricles to fill with blood between heartbeats. This is the least common kind of cardiomyopathy in children. It is sometimes linked with a gene problem, but often doctors cannot find a cause.

The condition can happen in babies whose heart lining is thicker than normal.

It can also develop in children if another condition or treatment causes scar tissue to build up in their heart muscle. One example would be radiation therapy for cancer.

To help the heart pump better, doctors use medicines like these: 

• Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), which reduce the workload on the heart and can slow the worsening of cardiomyopathy.
• Entresto, a newer medicine that combines an ARB (valsartan) with another medicine called sacubitril. These work together to better reduce the workload of the heart and slow the worsening of cardiomyopathy.
• Beta-blockers, which reduce the workload on the heart by lowering the blood pressure and slowing the heart rate.
• Digoxin, which makes the heart beat slower and with more force.
• Diuretics, which help the kidneys rid the body of extra water via the urine. This lowers the amount of fluid in the lungs and other tissues and may improve heart failure symptoms.
• Anticoagulants, or anticlotting medicines, which help prevent or dissolve clots that might form in the heart or blood vessels. When the heart is enlarged and weak, blood flow is slower, which may lead to clots forming.
• Medicines that correct the heart rate or make an irregular heartbeat normal if your child needs treatment for arrhythmia.

A pacemaker is a small device that doctors implant in your child’s chest. A wire attaches the pacemaker to an electrode. The electrode is placed in the heart wall. Small electrical impulses travel from a special battery through the wire to the heart, telling the heart when to beat.

A defibrillator is similar to a pacemaker.\

It monitors your child’s heart all the time for life-threatening rhythm problems. When it detects a problem, it sends an electrical shock to the heart to bring it back to a normal rhythm.

Sometimes, a child’s heart can become so weak that it needs more help than medicines can provide. In these cases, cardiac surgeons can connect the child’s heart to a mechanical pump that does the work of the heart. This kind of pump is called a VAD, and it can be placed inside or outside the body. VADs can support either the left or right ventricle or both. A VAD can be used for patients waiting for a heart transplant or for patients whose heart muscle needs time to rest and recover from an injury or infection.

AJ’s Story

When a virus attacked AJ’s heart, his team at Seattle Children’s recommended a ventricular assist device (VAD). The CentriMag pump allowed his heart to rest, heal and recover.

The heart transplant team at Seattle Children’s performs many transplants each year for children with cardiomyopathy or other heart problems that cannot be controlled using other treatments. Read more about our heart transplant program.

• Our team of 40+ pediatric cardiologists diagnoses and treats cardiomyopathy in children of all ages, from infants to young adults.
• A dedicated group of these doctors specializes in caring for children with cardiomyopathy and heart failure. They work closely with other Heart Center specialists – like our pediatric cardiac surgeons, cardiac catheterization team, electrophysiology team and cardiac nurses, nutritionists and pharmacists – to provide the highest level of care.
• Our 4 cardiac surgeons perform more than 500 procedures yearly. They have deep experience operating on babies, children and teens who need surgery, like placement of a pacemaker, defibrillator or ventricular assist device or a heart transplant.
• We also have a pediatric cardiac anesthesia team and a Cardiac Intensive Care Unit ready to care for children who undergo heart surgery.
• If your child has more than 1 condition, we make sure they get all the care they need. We involve doctors from other Seattle Children’s teams to meet your child’s needs, such as doctors who specialize in the kidneys, lungs or gastrointestinal system or the health of newborns. Heart Center doctors work closely with oncologists if cancer treatment affects your child’s heart.

 “I can’t imagine getting any better care than what Adrian had at Seattle Children’s. Each team was always extremely helpful and informative. We knew exactly what was going on from an hour-to-hour, day-to-day basis.”

– Earl Peterson, whose son Adrian received a ventricular assist device and then a heart transplant at Seattle Children’s

• Our Heart Failure Program is the only subspecialty of its kind in the Northwest.
• Our surgical outcomes are among the best in the nation year after year.
• Seattle Children’s has been named a Cardiomyopathy Center of Care by the Children’s Cardiomyopathy Foundation. The foundation is a national nonprofit committed to improving the health outcomes and quality of life for children with this condition.

• We match your child’s care to their symptoms and needs. Some children need only medicines for cardiomyopathy. Others need an implanted device to help their heart beat or to take over some of the heart’s work. In the most severe cases, a child may need a heart transplant. Your child’s treatment plan is custom-made for them.
• With regular visits and careful monitoring, we check how your child is doing over time. As their needs change, we adjust their care to get the best results. We always take into account their age, growth and development.
• At Seattle Children’s, we have the expertise to take care of children of all ages, from newborns to young adults.

• We are committed to your child’s overall health and well-being and to helping your child live a full and active life.
• Whatever types of care your child needs, we will help your family through this experience. We will discuss your child’s condition and treatment options in ways you understand and involve you in every decision.
• Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.
• Seattle Children’s has many resources, from financial to spiritual, to support your child and your family and make the journey as smooth as possible.
• Many children and families travel to Seattle Children’s for heart surgery or other care. We help you coordinate travel and housing so you can stay focused on your child.

• Doctors and scientists at Seattle Children’s are working to advance treatment for cardiomyopathy and enhance the quality of life for children living with this condition.
• We take part in multicenter clinical trials to study medicines for children with cardiomyopathy and heart failure and ways to improve outcomes for children who have ventricular assist devices or need a heart transplant.