Before birth

It's possible for a baby to be diagnosed with hypoplastic left heart syndrome while it's still in the womb. Your doctor may be able to identify the condition on a routine ultrasound exam during the second trimester of pregnancy.

After birth

After your baby is born, his or her doctor may suspect a heart defect, such as hypoplastic left heart syndrome, if your baby has grayish-blue skin or has trouble breathing. Your baby's doctor may also suspect a heart defect if he or she hears a heart murmur — an abnormal whooshing sound caused by turbulent blood flow.

Doctors usually use an echocardiogram to diagnose hypoplastic left heart syndrome. This test uses high-pitched sound waves that bounce off your baby's heart to produce moving images that can be viewed on a video screen. In a baby with hypoplastic left heart syndrome, the echocardiogram reveals a smaller than normal left ventricle and aorta, and it may also show abnormal mitral or aortic valves.

Because this test can track blood flow, it also shows blood moving from the right ventricle into the aorta. In addition, an echocardiogram can identify associated heart defects, such as an atrial septal defect.


Hypoplastic left heart syndrome is treated through several surgical procedures or a heart transplant. Your doctor will discuss with you the treatment options for your child.

If the diagnosis has been made before the baby is born, doctors usually recommend delivery at a hospital with a cardiac surgery center.

Before surgery

Your baby's doctor may recommend several options to help manage your baby's condition before surgery or transplant. They may include:

  • Medication. The medication alprostadil (Prostin VR Pediatric) helps dilate the blood vessels and keeps the ductus arteriosus open.
  • Breathing assistance. If your baby has trouble breathing, he or she may need help from a breathing machine (ventilator), which ensures adequate oxygen delivery.
  • Intravenous fluids. Your baby will receive fluids through a tube inserted into a vein.
  • Feeding tube. If your baby has trouble or gets tired feeding, he or she may be fed through a feeding tube.
  • Atrial septostomy. This procedure creates or enlarges the opening between the heart's upper chambers (atria) to allow more blood flow from the right atrium to the left atrium if the foramen ovale closes. If your baby already has an atrial septal defect, an atrial septostomy may not be necessary.


Your child will likely need several surgical procedures to treat hypoplastic left heart syndrome. Surgeons perform these procedures in three stages. These procedures are designed to create normal blood flow in and out of the heart, allowing the body to receive the oxygen-rich blood it needs.

  • Norwood procedure. This surgery is usually performed within the first two weeks of your child's life. Several forms of this procedure may be performed.

    Surgeons reconstruct the aorta and connect it directly to the heart's lower right chamber (right ventricle). Surgeons insert a tube (shunt) that connects the aorta to the arteries leading to the lungs (pulmonary arteries), or they place a shunt that connects the right ventricle to the pulmonary arteries. This procedure allows the right ventricle to effectively pump blood to both the lungs and the body.

    In some cases, doctors may perform a hybrid procedure. Surgeons implant a stent in the ductus arteriosus to maintain the opening between the pulmonary artery and aorta, place bands around the pulmonary arteries to reduce blood flow to the lungs, and create an opening between the atria of the heart.

    After this procedure, your baby's skin will still have a blue cast because oxygen-rich blood and oxygen-poor blood continue to mix within the heart. Once your baby successfully passes through this stage of treatment, the odds of survival may increase, but he or she may still be at risk of death due to complications.

  • Bi-directional Glenn procedure. This procedure is generally performed when your child is between 3 and 6 months of age, after the first procedure. In this procedure, doctors remove the first shunt attached to the pulmonary arteries, and then connect one of the large veins that normally returns blood to the heart (the superior vena cava) to the pulmonary artery instead. If surgeons previously performed a hybrid procedure, they'll conduct additional steps during this procedure.

    This procedure reduces the work of the right ventricle by allowing it to pump blood mainly to the aorta. It also allows most of the oxygen-poor blood returning from the body to flow directly into the lungs without a pump.

    After this procedure, all the blood returning from the upper body is sent to the lungs, so blood with more oxygen is pumped to the aorta to supply organs and tissues throughout the body.

  • Fontan procedure. This procedure is usually performed when your child is between 18 months and 4 years of age. During this procedure, the surgeon creates a path for the oxygen-poor blood in one of the blood vessels that returns blood to the heart (the inferior vena cava) to flow directly into the pulmonary arteries. The pulmonary arteries then transport the blood into the lungs.

    This procedure allows the rest of the oxygen-poor blood returning from the body to flow to the lungs. After this procedure, there's no mixing of oxygen-rich and oxygen-poor blood in the heart, and your child's skin will no longer look blue.

Another surgical option is a heart transplant, especially when the defects are complex. Babies with hypoplastic left heart syndrome can be considered for a transplant. While awaiting a heart transplant, your baby may require medications until a donor heart becomes available.

Follow-up care

After surgery or a transplant, your baby will need lifelong follow-up care with a cardiologist trained in congenital heart diseases to monitor his or her heart health. Various complications may occur over time and may require further treatment or medications.

Some medications may be necessary to regulate heart function. If your baby receives a heart transplant, anti-rejection medications will be necessary for the rest of his or her life to combat rejection of the new heart.

Your child's cardiologist will tell you whether your child needs to take preventive antibiotics before certain dental or other procedures to prevent infections. In some cases, he or she may also recommend that your child limit physical activity.

Your doctor will likely recommend that you continue to have regular follow-up appointments with a cardiologist trained in congenital heart diseases as an adult. If you're a woman and you're considering pregnancy, discuss pregnancy risks with your doctor.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

Coping and support

Caring for a baby with a serious heart problem, such as hypoplastic left heart syndrome, can be challenging. Here are some strategies that may help make it easier:

  • Seek support. Ask for help from family members and friends. Talk with your child's cardiologist about support groups and other types of assistance that are available near you.
  • Record your baby's health history. It will be important to write down your baby's diagnosis, medications, surgery and other procedures and the dates they were performed, as well as the name and phone number of your child's cardiologist, emergency contact numbers for your child's doctors and hospital, and any other important information about your baby's care. It's also important to include a copy of the operative report from your child's surgeon in your records.

    This information will help you recall the care your child has received, and it will be useful for doctors who are unfamiliar with your baby to review his or her complex health history.

  • Talk about your concerns. As your child grows, you may worry about activities in which he or she can safely participate. Talk with the cardiologist about which activities are best for your child. If some are off-limits, encourage your child in other pursuits rather than focusing on what he or she can't do. If other issues about your child's health concern you, discuss them with your child's cardiologist, too.

Although every circumstance is different, remember that many children with congenital heart defects grow up to lead healthy lives.

Hypoplastic left heart syndrome care at Mayo Clinic

March 03, 2018
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