Hypoplastic Left Heart Syndrome (HLHS)

Also known as: HLHS

What is Hypoplastic Left Heart Syndrome?

Hypoplastic left heart syndrome (HLHS) is one of the most complex cardiac defects seen in newborns. Children diagnosed with hypoplastic left heart syndrome have all of the structures on the left side of the heart, which receive oxygenated blood from the lungs, severely undeveloped.

What are the signs/symptoms of HLHS?

Babies with HLHS typically display the following:

  • Lower than normal oxygen saturation
  • Cyanosis, a blue skin color indicating a decrease in oxygen in the bloodstream
  • Difficulty breathing (rapid breathing or shortness of breath)
  • Low pulse
  • Lethargy 

What causes HLHS?

Most of the time this heart defect occurs by chance, with no clear reason for its development.

How is HLHS diagnosed?

Hypoplastic left heart syndrome is one of the most readily diagnosed on fetal echocardiograms and is one of the most common cardiac defects picked up on an obstetrical ultrasounds.

Treatment for Hypoplastic Left Heart Syndrome

Surgery for babies with HLHS will allow their heart to pump blood better to the lungs and the rest of the body. The surgery is conducted in three phases during the first few years of life.

  1. The first phase, called the Norwood procedure, is usually performed in the first weeks of life and includes the building of a new aorta.
  2. The second phase, called the Glenn operation, is usually performed between four and six months of age. This procedure connects the major vein carrying blood from the top half of the body directly to blood vessels to the lungs to get oxygen.
  3. The last phase, the Fontan procedure, is usually performed around three to four years of age. The exact procedures and timing depend on your child’s condition.

Reviewed by: Anthony F. Rossi, MD

This page was last updated on: December 18, 2020 04:59 PM

Pediatric Cardiology: Heart Institute

The Heart Institute– a world leader in pediatric cardiology and cardiovascular surgery and the care of children with congenital heart disorders – serves as a beacon to families confronting the reality of a child or newborn with a heart defect.

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Cyanosis

A bluish tinge of the lips, tongue, nail beds or skin is called cyanosis. There are 2 types: Central cyanosis and Acrocyanosis. Central cyanosis occurs because of a lack of oxygen in the red cells of blood and is never normal. Acrocyanosis is usually normal in babies and occurs when the extremities (hands and feet are cold), appear blue but not the lips, or tongue which normally appear pink in color. Learn more

Bidirectional Glenn Procedure

Bidirectional Glenn procedure is one in a series of surgeries performed to get a sufficient amount of blood to the lungs. It is needed when one of the heart’s ventricles doesn’t work well. Learn more

Norwood Procedure

Hypoplastic left heart syndrome is a heart defect that’s characterized by an undeveloped left ventricle that causes a number of problems. Norwood procedure is a cutting-edge three-step surgery that corrects the problem with a good success rate. Learn more