Children's Hospital Colorado

Hypoplastic Left Heart Syndrome (HLHS)

Pediatric hypoplastic left heart syndrome

Children with hypoplastic left heart syndrome (HLHS) have a small, underdeveloped left side of the heart. This may involve all or some parts of the left heart, including the aorta, aortic valve, left ventricle and mitral valve. The left side of the heart is so underdeveloped that it cannot pump enough blood to the body.

At Children's Hospital Colorado, experts in the Colorado Fetal Care Center and Heart Institute have decades of experience caring for patients with HLHS. If your baby is diagnosed before birth, experts in our Fetal Cardiology Program will design a care plan that is right for both mother and baby. We'll be with you every step of the way, from diagnosis and delivery to follow-up visits. After your baby's birth, experts in our Single Ventricle Care Program will provide lifelong care for your child to help them thrive.

Watch the video below to learn how Oliver's family found hope following a prenatal HLHS diagnosis:

What is hypoplastic left heart syndrome?

Hypoplastic left heart syndrome is a congenital heart defect, meaning kids are born with the disease. With this condition, the only way for blood to get to the body is if it can pass back through the heart from the left atrium to the right atrium and ventricle.

Then, the blood passes through the pulmonary artery and through a small hole called the ductus arteriosus that connects to the aorta. The ductus arteriosus is one of the heart structures that allow a baby's heart to function in the womb, but it starts to close very soon after birth. This prevents blood from flowing properly, which is why early diagnosis and treatment are so critical.

Who gets hypoplastic left heart syndrome?

Hypoplastic left heart syndrome is more common in boys than girls, although the reason is not known. About 8% of kids with congenital heart defects have hypoplastic left heart syndrome.

See why our outcomes make us one of the top heart hospitals
The Connection Journey
Giving hope a heartbeat

After a devastating diagnosis, there still can be hope. We connected a family just diagnosed with HLHS with a family who's been there — to answer questions, to shed light and to offer hope — from diagnosis to surgery to recovery.

Watch their stories

Get to know our pediatric experts.

Jeniann Yi, MD

Jeniann Yi, MD

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Sara Mackie, NP

Sara Mackie, NP

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Eduardo Da Cruz, MD

Eduardo Da Cruz, MD

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