Hypoplastic left heart syndrome (HLHS) in children

LIke ThisLIke ThisLIke ThisLIke ThisLIke This

Contact the Complex Biventricular Repair Program

Wayne Tworetzky, MD, Co-Director of the Advanced Fetal Care Center at Boston Children's Hospital, describes the congenital heart defect hypoplastic left heart syndrome (HLHS) in our Pediatric Playbooks series.

If a prenatal ultrasound has revealed that your baby will be born with hypoplastic left heart syndrome (HLHS)—or if your infant has been diagnosed with HLHS—an understanding of the condition will help you plan for, and cope with, this rare and complex congenital (present at birth) heart defect.

While this condition is very serious, children with HLHS can undergo therapy at Boston Children's Hospital—shortly after birth or in some select situations, while your baby is in utero.

In the infant and child with a normal heart…

Oxygen-poor (blue) blood returns to the right atrium from the body, enters the right ventricle and is pumped through the pulmonary artery into the lungs to receive oxygen. The oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left ventricle and is pumped out to the body through the aorta.

Diagram of Normal Heart


  • Most of the structures on the left side of the heart are too small and underdeveloped (hypoplastic) to provide enough red blood flow for the body’s needs.
  • The small left ventricle, which needs to be large enough and strong enough to pump blood out to the body, simply can’t function effectively.
  • Other left heart structures can also be underdeveloped in varying degrees—including the mitral valve, the aortic valve and the aorta itself.

How Boston Children’s Hospital approaches HLHS

The experienced surgeons in our Advanced Fetal Care Center and Cardiac Surgery Department understand how distressing a diagnosis of HLHS can be for parents. Ranked #1 for heart care and heart surgery in 2010, Children’s takes an innovative approach to treating HLHS—including the world’s largest and most experienced program for fetal cardiac intervention.

You can have peace of mind knowing that Boston Children’s surgeons treat a high volume of some of the most complex pediatric heart conditions in the world, with excellent success rates. We’re home to some of the world’s foremost pediatric physicians and researchers. And we provide families with a wealth of information, resources, coordination and support—before, during and after your child’s treatment.

With our compassionate, family-centered team of caregivers providing expert treatment, follow-up and aftercare, you and your baby are in the best possible hands.

HLHS @ Boston Children's featured on National Public Radio

Listen as Boston Children's cardiologist Wayne Tworetzky, MD, describes our unique expertise in a special treatment for some cases of HLHS—fetal intervention, or operating on the baby's heart while she's still in utero. The NPR radio segment is called, "Stitch in Time: Fixing a Heart Defect Before Birth." 

Screening neurodevelopment problems 

Children who’ve had surgery for heart disease as infants are at greater risk of neurodevelopmental problems. By school age, they tend to have more academic, behavioral and coordination difficulties than other children. Boston Children’s Cardiac Neurodevelopment Program—one of just a handful in the United States—provides expert screening, evaluation and care for infants, children and teens with congenital heart disease who are at risk for neurodevelopmental problems. Screening begins soon after your child’s first cardiac surgery and continues as your child grows to make sure she’s hitting her developmental milestones. 

 See why we're #1
 Boston Children's Heart Center ranked #1 in U.S. News & World Report for eight consecutive years. Learn more.

Hypoplastic left heart syndrome: Reviewed by Wayne Tworetzky, MD
© Boston Children's Hospital, 2010

The future of pediatrics will be forged by thinking differently, breaking paradigms and joining together in a shared vision of tackling the toughest challenges before us.”
- Sandra L. Fenwick, President and CEO

Boston Children's Hospital 300 Longwood Avenue, Boston, MA 02115 617-355-6000 | 800-355-7944