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Hypoplastic left heart syndrome (HLHS)

Hypoplastic left heart syndrome is a series of heart defects that affect the left side of a newborn's heart. The cause is unknown, but we know it develops during gestation. In HLHS, the lower left heart chamber (ventricle) is too small and therefore cannot adequately pump blood through the aorta out to the body. Additionally, the aortic and mitral valves do not work properly and the aorta is much smaller than normal.

How do we diagnose HLHS?

For the first several days of life, a newborn will have a patent ductus arteriosus (PDA). This allows blood to be pumped from the right ventricle to both the lungs and the body. However, when this closes (within the first five days life), the right side has no way of pumping the blood to the body. Also, the left ventricle and aorta are too small to provide an adequate blood supply. Following this, the newborn will begin to exhibit symptoms such as shortness of breath, rapid breathing, pounding heart, bluish skin from lack of circulation, cold arms and legs, poor pulse, difficulty feeding, and overall lethargy.

In recent years, there has been an increased ability to detect this defect during the gestational period by ultrasonography. During the newborn period, an echocardiogram can usually identify this defect.

Hypoplastic left heart syndrome (HLHS)

How we treat hypoplastic left heart syndrome

Norwood operation

This surgery is performed within the first two weeks of life. The surgeon will reconstruct the aorta and connect it directly to the heart's right ventricle. This will allow better blood flow out to the body. Your child may still appear slightly blue because of the oxygen-rich and oxygen-poor blood mix in the right ventricle.

Bidirectional Glenn shunt or hemi-Fontan procedure

This is the second stage, usually happening around four to six months of life. This procedure involves connecting the superior vena cava directly to the lungs. It will reduce the workload on the right ventricle and allow it to pump blood mainly through the aorta. Additionally, because most of the oxygen-poor blood is being routed directly to the lungs, more oxygen-rich blood is being pumped out to the body. However, your infant will still appear blue because there is some oxygen-poor blood entering the right side of the heart.

The Fontan

This procedure is done sometime between 18 months to three years of age. During this surgery, the inferior vena cava is connected directly to the lungs. This prevents oxygen-poor and oxygen-rich blood from mixing. It uses the right ventricle to pump oxygen-rich blood out to the body through the aorta. Following this procedure, the right ventricle is the only pumping chamber of the heart. Your child's color will return to normal.

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