Heart and Blood Conditions


  • Schedule an appointment +

    • For appointments in Seattle, Bellevue, Everett, Federal Way, Olympia, Tri-Cities and Wenatchee, call 206-987-2515.
    • For appointments in Tacoma and Silverdale, call 253-272-1812.
    • For appointments in Alaska, call 907-339-1945.
    • How to schedule

    If this is a medical emergency, call 911.

  • Find a doctor +

  • Locations +

    • Seattle Children's Main Campus: 206-987-2515
    • Bellevue Clinic and Surgery Center: 425-454-4644
    • Everett: 425-304-6080
    • South Clinic in Federal Way: 253-838-5878
    • Olympia: 360-459-5009
    • South Sound Cardiology Clinics: 253-272-1812
    • Tri-Cities (Richland): 509-946-0976
    • Wenatchee: 509-662-9266
    • Pediatric Cardiology of Alaska: 907-339-1945
    • Seattle Children's doctors provide many cardiac services at regional sites throughout the Pacific Northwest. See our complete list of Heart Center locations.

  • Refer a patient +

    • If you are a provider, fax a New Appointment Request Form (NARF) (PDF) (DOC) to 206-985-3121 or 866-985-3121 (toll-free).
    • No pre-referral work-up is required for most conditions. If you have already done testing such as an EKG, Holter monitor or echocardiogram, please fax this information as well as relevant clinic notes and the NARF to 206-985-3121 or 866-985-3121 (toll-free).
    • Your patient will be seen as quickly as possible by the provider who is the best match for managing the current problem.
    • View our complete Heart Center Referral Information (PDF).

What is cardiomyopathy?

Cardiomyopathy (pronounced card-ee-oh-my-OP-ah-thee) is a disease of the heart's muscular wall, called the myocardium. It can also be a change in the heart that causes it to lose its pumping strength.

There are three main kinds of cardiomyopathy - dilated, hypertrophic and restrictive.

  • Dilated cardiomyopathy: the heart muscle is weakened and the heart becomes enlarged and stretched.
  • Hypertrophic cardiomyopathy: the heart muscle is too thick, which can cause a problem in the way the heart fills with blood and/or how it pumps blood out to the body.
  • Restrictive cardiomyopathy: the heart muscle becomes very stiff so it is harder for the lower chambers of the heart (ventricles) to fill with blood between heartbeats.

In each case, cardiomyopathy reduces the heart's ability to pump blood effectively and can lead to congestive heart failure.

Cardiomyopathy in Children

The most common kind of cardiomyopathy in children is dilated cardiomyopathy. Viral infections (viruses) are a common cause. These infections can irritate the heart muscle (a condition called myocarditis) and weaken it. To try keeping up with the body's need for blood and oxygen, the heart works harder and expands (gets bigger).

Other forms of dilated cardiomyopathy are genetic, meaning it can be inherited (passed down from parents to children in their genes) and runs in families. Sometimes, no cause can be identified. Doctors call this "idiopathic" dilated cardiomyopathy.

Hypertrophic cardiomyopathy is usually caused by a problem with one or more genes that are involved with heart muscle development. Some babies born with this type of cardiomyopathy show signs of an abnormal heart at birth, but in many people, it is not diagnosed until later in life. Hypertrophic cardiomyopathy can also develop after birth because of some other health problem, such as acromegaly (a hormone problem that causes excess growth).

Restrictive cardiomyopathy is the least common kind. It is rare in children, and is sometimes associated with a gene problem, but often no cause is identified. The condition can occur in babies born with an unusually thick lining in their heart. It can also develop in children if another condition causes scar tissue or some other kind of cell to build up in their heart muscle. One example would be a tumor that invades the heart.

Cardiomyopathy at Seattle Children's

Our heart team has treated many children with cardiomyopathy. Our heart failure service is the only subspecialty of its kind in the Northwest. We have extensive experience with the diagnosis and the treatment these patients may require, including medicines, a pacemaker, a defibrillator,or a ventricular assist device.

When you come to Seattle Children's, a team of people will take care of your child. The cardiomyopathy and heart failure team includes not only your cardiologist (heart doctor), but also a group of specially trained heart failure nurses, geneticists with special interest in genetic cardiomyopathies, cardiac nutritionists, child life specialists and social workers. If your child requires hospitalization, care will be provided by specialized pediatric cardiac nurses, cardiac intensive care doctors (if your child is very sick), neonatologists, pulmonologists (lung doctors) and others, if their expertise is needed. We work together to meet all of your child's health needs and help your family through this experience.

Seattle Children's has been treating children since 1907. Our team members are trained in their fields and also in meeting the unique needs of children. For example, the doctors who give your child anesthesia are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

Contact Us

Contact the Heart Center at 206-987-2015 for a cardiac referral, a second opinion or more information.