Hypoplastic Left Heart Syndrome

With hypoplastic left heart syndrome (HLHS), a baby is born with an abnormality of the heart or heart valves that results in the left side of the heart being smaller and weaker than it should be. The left side of the heart can’t do its job pumping blood through the body.

As the leading providers of pediatric heart care in Louisville and Southern Indiana, our specialists are experienced with successfully treating hypoplastic left heart syndrome.

The board-certified and fellowship-trained specialists at Norton Children’s Heart Institute, affiliated with the University of Louisville, have the skill and experience to provide a pinpoint diagnosis and develop a customized treatment plan for you and your child.

Since the left side of the heart doesn’t work correctly, the right side of the newborn’s heart has to work harder, and there has to be a connection between the right and left sides of the baby’s circulations so blood can get to the only functioning ventricle. Babies born with hypoplastic left heart syndrome need an atrial septal defect — a hole between the right and left chambers of the heart. Babies born with HLHS but without this hole will need an emergency intervention called a balloon septostomy shortly after birth to create such a hole.

The atrial septal defect and a normal opening in a newborn’s heart — the patent ductus arteriosus (PDA)— allow the heart to pump blood to both the lungs and throughout the body. Normally, the PDA shrinks and closes during the first few days of life. In a baby with HLHS, the PDA must stay open so blood can flow to the body. Prostaglandins are a medication frequently given to babies with HLHS after birth to keep the PDA open.

The cardiothoracic specialists at Norton Children’s Heart Institute are trained to act swiftly to keep the PDA and the ASD open until the heart is repaired.

Hypoplastic left heart syndrome diagnosis

Hypoplastic left heart syndrome may be seen on ultrasound scans during pregnancy. A fetal echocardiogram provides more information and tells the delivery team how to prepare for care after birth.

Common tests used to learn more about a newborn’s heart include:

Hypoplastic left heart syndrome treatment

HLHS will be diagnosed through ultrasound before the baby’s birth, preparing the cardiothoracic specialists at Norton Children’s Heart Institute to move swiftly to stabilize the newborn. Babies born showing the first signs of HLHS will be stabilized immediately while more diagnostic tests are being performed.

One of the first treatments is a medication called prostaglandin that is used to keep the patent ductus arteriosus open. Doctors will use medications and mechanical ventilation strategies (breathing assistance) to balance how much blood flows to the body and how much goes to the lungs.

In the past, this condition often was considered inoperable. Today, many babies with HLHS are treated with a series of three surgeries. In some cases, a child with hypoplastic left heart syndrome may need a heart transplant because the case is so complex or because the heart becomes weak after surgery.

The three surgeries for HLHS are:

The Norwood procedure

  • This surgery is typically done in the first week of a baby’s life.
  • Cardiothoracic surgeons create a new aorta to connect to the right ventricle.
  • A tube is placed from either the large arteries off the aorta or the right ventricle and connected to the blood vessels supplying the lungs, also known as the pulmonary arteries.
  • The right ventricle is then able to pump blood to both the lungs and the rest of the body.

The Glenn procedure

  • This surgery is typically performed when the infant is 4 to 6 months old.
  • Cardiothoracic surgeons create a direct connection between the pulmonary artery and the superior vena cava, the blood vessel that returns oxygen-poor blood from the upper part of the body to the heart.
  • The procedure reduces the work of the right ventricle by allowing blood returning from the body to flow directly to the lungs.

The Fontan procedure

  • This surgery is typically performed when the child is 2 to 4 years old.
  • Cardiothoracic surgeons connect the pulmonary artery and the inferior vena cava, the blood vessel that returns oxygen-poor blood from the lower part of the body to the heart.
  • This procedure allows the rest of the blood coming back from the body to go to the lungs.
  • Once this procedure is complete, oxygen-rich and oxygen-poor blood will no longer mix in the heart and the child’s skin will no longer look bluish.
  • Some patients will have a “fenestration” (opening) connecting the venous and arterial circulations, which allows mixing to periodically occur.

These surgeries don’t cure HLHS. The child will need regular follow-up visits with a pediatric cardiologist to monitor progress. Even when the child becomes an adult, a congenital heart defect specialist will continue to provide care.

Why Norton Children’s Heart Institute?

Norton Children’s Heart Institute, affiliated with the University of Louisville, is a comprehensive pediatric heart surgery, heart failure and heart transplant program serving Kentucky, Southern Indiana and beyond.

The goal of the full-service Norton Children’s Heart Institute is to provide care for the child and the whole family. Our specialists are prepared to repair even the most complex congenital and acquired heart conditions.

Our heart team includes:

  • Pediatric cardiothoracic surgeons
  • Pediatric transplant surgeons
  • Pediatric cardiologists
    • Fetal cardiologists
    • Adult congenital heart cardiologists
    • Heart failure/heart transplant cardiologists
    • Pediatric electrophysiologists
    • Pediatric cardiac catheterization cardiologists
  • Pediatric cardiovascular anesthesiologists
  • Pediatric intensive care physicians
  • Cardiac critical care nurses
  • Critical care pharmacists
  • Family support team
  • Child life specialists
  • Rehabilitation specialists
  • Social workers
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Norton Children’s Heart Institute

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(502) 629-2929

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