Hypoplastic Left Heart Syndrome (HLHS)
Welcome to the HLHS Parent information page.  This site was designed by parents of a child with HLHS to help other parents receiving the diagnosis of Hypoplastic Left Heart Syndrome (HLHS).  Approximately 30-45% of HLHS cases are diagnosed prenatally (before birth.)  This can allow time for parents to research the condition and find an appropriate surgical center.  This site is designed to provide parents receiving a prenatal diagnosis of HLHS questions to ask to assist in finding the best medical care.  Some of this information may also be helpful for parents who do not get the diagnosis of HLHS until after the baby is born.  

Please note that information on HLHS and the surgical options is continuing to grow and change. There are several different variations of surgeries, and the number of hospitals performing surgical procedures has expanded rapidly since we began this website in 2001.

If your child has been diagnosed with another single ventricle defect such as: Hypoplastic Right Heart Syndrome (HRHS), Tricuspid Atresia, Double Inlet Left Ventricle (DILV), Double Outlet Right Ventricle (DORV), or Single Ventricle much of this site will still be applicable to you.  Please see the following links for descriptions and diagrams of HLHS and other single ventricle anomalies: 
CovePoint Foundation - interactive diagrams
Cincinnati Children's Hospital - video of HLHS
Society of Thoracic Surgeons
Children's Hospital of Boston 
Children's Hospital of Philadelphia 

Prenatal Diagnosis    

Receiving your baby's diagnosis of HLHS can be frightening and overwhelming.  The important thing to know is that there is hope.   Fortunately, there are now surgical options which can successfully treat babies with HLHS.  If you have received the diagnosis while you are pregnant, you have time to learn about the condition, and make some important decisions:  

1) Which treatment option to pursue: Heart Transplant, the 3-Stage Surgical Procedure or a fetal intervention (see below).
2) Where to deliver the baby 
3) Where to have the baby's surgery performed.  

Fetal Interventions:  There are also some fetal interventions for which some may qualify.  This procedure is done during pregnancy to hopefully prevent HLHS from occurring at birth, or reducing the severity of the condition.  The results are mixed, and it does carry risks to the baby and mother.  Please see the following links on information on fetal interventions:
Children's Hospital of Boston
CS Mott Children's Hospital
Children's Hospital of Philadelphia

To help you make these decisions, this web site contains:
* Some basic information on HLHS (see below)
* Surgical options for HLHS
* Considerations in finding an appropriate surgical center/hospital.
Frequently Asked Questions about having a baby with HLHS
* Basic descriptions of the two main surgical options - heart transplant and the 3-stage surgery
* A list of questions to ask your insurance company, the surgeon and the hospital 

Please note that this web site was created by the parents of a child with HLHS, and not medical professionals.  It is not intended as medical advice, merely a guide to help you understand the condition and your options.  Consult your physician with any questions you may have regarding HLHS.
This web site is not intended as medical advice.  Please consult your physician with any questions you may have regarding your child's condition.

Copyright © 2001-2019 D.L. Hilton-Kamm, all rights reserved. 
Hypoplastic Left Heart Syndrome (HLHS)
Information Page
Hypoplastic Left Heart Syndrome (HLHS) is a condition in which the left side of the heart is underdeveloped.  Usually, the left ventricle, the left atrium, the mitral valve and the aorta are affected.  It is called a syndrome because it can encompass several different variations and varying degrees of development of these parts of the heart. 

To understand HLHS, it is helpful to understand how a normal baby's heart works.  The heart is comprised of four chambers: the upper chambers are called the left and right atria, and the lower chambers are called the left and right ventricles.  

Very simply, in a healthy heart blood flows from the right atrium to the right ventricle where it is then pumped through the pulmonary artery to the lungs to be oxygenated.  Blood then flows back to the heart via the left atrium to the left ventricle, which pumps this oxygenated blood through the aorta out to the body.  This is how the body's organs and tissue receive oxygen, which is vital.  When a baby has HLHS, the left side of the heart is underdeveloped so it cannot sufficiently pump the oxygenated blood out to the body. 

Babies with HLHS do not have problems while in the womb - it is only after birth that the heart fails to work properly.  This is because all babies receive oxygen from the placenta while in the womb, so blood does not need to go to the lungs.  In addition, there is an opening between the pulmonary artery and the aorta, called the patent ductus arteriosus (PDA) that is present in all babies.  It allows the blood to go from the right ventricle out to the body, bypassing the left side of the heart.  

The PDA usually closes a few days after birth, separating the left and right sides of the heart.  It is at this time that babies with undetected HLHS will exhibit problems as they experience a lack of blood flow to the body.  They may look blue, have trouble eating, and breathe rapidly.  If left untreated, this heart defect is fatal - usually within the first few days or weeks of life.  

Once HLHS has been diagnosed, a drug called prostaglandin is given to keep the PDA open until surgery is performed.  There are two surgical options for treating HLHS:  a Heart Transplant or the 3-Stage Surgical Procedure, the first stage of which is called the Norwood procedure.  (For bloodless surgical options, please see the Columbus Children's Hospital website.)

Our Mission

This page was last updated on: February 22, 2019
You can view our sister site:
California Heart Connection  
CHD Resources
for information and tips on taking care of your baby with HLHS, and  resources for parents as your child grows.