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What is hypoplastic left heart syndrome (HLHS)?

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect in which the left side of the heart is                                            Ruby Anne

underdeveloped.

In a normal heart, the heart’s left side has the job of pumping oxygenated blood into the aorta, the large artery that carries blood to the body. In a child with HLHS:

  • The mitral valve, which separates the upper and lower left chambers of the heart, is too small or completely closed (atretic).
  • The left ventricle (the lower, pumping chamber) is very small.
  • The aortic valve, which separates the left ventricle and the aorta, is too small or completely closed (atretic).
  • In addition to the most common form of HLHS shown in the animation below, there are a number of similar complex cardiac conditions sometimes called “HLHS variants.” In these children, the treatment strategy is similar to those with the more typical HLHS, which is shown in the animations below.

    Signs and symptoms of HLHS

    The following symptoms of hypoplastic left heart syndrome may be present at birth or several days later:

    • Blue or purple tint to lips, skin and nails (cyanosis)
    • Difficulty breathing
    • Difficulty feeding
    • Lethargy (sleepy or unresponsive)

    • Testing and diagnosis of HLHS

      Often, hypoplastic left heart syndrome is diagnosed before birth, with fetal echocardiogram (ultrasound).

      Sometimes HLHS is diagnosed hours or days after birth and the baby will need immediate therapy. Diagnosis of HLHS may require some or all these tests:

      • Echocardiogram (also called “echo” or ultrasound): sound waves create an image of the heart
      • Electrocardiogram (ECG): a record of the electrical activity of the heart
      • Chest x-ray
      • Pulse oximetry: a noninvasive way to monitor the oxygen content of the blood
      • Cardiac catheterization: a thin tube is inserted into the heart through a vein and/or artery in the leg which makes measurements throughout the heart
      • Cardiac MRI: a three-dimensional image shows the heart’s structures in detail

Treatment for hypoplastic left heart syndrome

Hypoplastic left heart syndrome is most often fatal without early intervention. Compared to 35 years ago, there are now many different options for treatm

ent of this complex heart condition; an individualized approach is taken for each and every child. Your doctor will explain each individual option, and why one particular approach might be recommended for your child.

Hypoplastic left heart syndrome surgery

Typically, your child will require open heart surgery to re-direct the oxygen-rich (“red”) blood and oxygen-poor (“blue”) blood. After these operations:

  • The right side of the heart will do what is usually the job of the left side — pumping oxygenated blood to the body.
  • The deoxygenated blood will flow from the veins to the lungs without passing through the heart.

The series of three reconstructive operations to repair HLHS — the Norwood, Glenn and Fontan procedures — is known as “Staged Reconstruction.” Surgeons reconfigure the heart and circulatory system during these procedures.

Stage 1: Norwood procedure

This operation will occur within several days of birth. Depending on the type of heart defect, different surgical procedures may be used, including the Norwood procedure. The purpose of this operation is to ensure that blood flow is controlled enough to prevent damage to the heart and lungs, and that enough blood is reaching the lungs to keep the child alive until the second operation.

Stage 2: Hemi-Fontan or Glenn operation

The second procedure, known as the hemi-Fontan or Glenn operation usually occurs within six months of birth. During this surgery the superior vena cava — a large vein that carries deoxygenated blood from the upper body into the heart — is disconnected from the heart and attached to the pulmonary artery. After this operation, deoxygenated blood from the upper body goes directly to the lungs without passing through the heart.

Stage 3: Fontan procedure

This operation, called the Fontan procedure, occurs at approximately 1 1/2 to 3 years of age. During this surgery the inferior vena cava, a large vein that carries deoxygenated blood from the lower body into the heart, is disconnected from the heart and attached to the pulmonary artery. After this operation, all of the deoxygenated blood from the body goes directly to the lungs without passing through the heart.

 

ABOUT THE ARMER FOUNDATION FOR KIDS:
Founded by Jennifer and Matt Armer in 2019, the Armer Foundation For Kids (a 501(c)(3) 84-2327428) works to reduce
financial barriers for families so that they can care for their children with chronic or life-altering diseases that can often
lead to unforeseen financial burdens. For more information and to see the children for which they are currently
fundraising, visit www.armerfoundation.org.

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