Hypoplastic left heart syndrome
Hypoplastic left heart syndrome (HLHS) is the abnormally small growth of the
heart's major pumping chamber, the left ventricle. HLHS occurs in about one
percent of all congenital heart disease. Essentially, the left ventricle is not
functioning because the valves leading into and out of it are severely tight or
not allowing any blood flow. Additionally, the main route out the left
ventricle, the aorta, is also underdeveloped or nonfunctioning.
Symptoms of HLHS
The newborn baby may initially appear to be well during the first hours
or even days of life. However, as
the baby breathes on his own, the pressure in his lungs begins to decrease. The baby will appear to be sick,
breathing quickly, not feeding, and showing a faster heart beat and congested
lungs.
Treatment for the condition
After a definitive diagnosis is formed, the baby will undergo the first
surgery, called the Norwood procedure. The pulmonary artery is separated from
the heart and connected to the small aorta. This enlarges the aorta and allows both
oxygenated and deoxygenated blood to get to the body via the open pulmonary
valve. Next a Gore-Tex tube is
placed between the subclavian artery, the artery that runs under the collar
bone, and the pulmonary artery to allow blood to flow from the baby's upper body
directly to the lungs, bypassing the heart altogether. From the lungs, blood flows to the heart
to be pumped out to the body, carrying oxygen.
When the child is five to eight months of age, the child will need to undergo
a second surgery called the Glenn procedure. The Glenn procedure connects the
superior vena cava to the pulmonary artery, after the Blalock-Taussig shunt is
separated. This allows even more blood flow through the pulmonary arteries to
the lungs. It also serves as a basis for the final surgery, the Fontan
procedure.
The Fontan procedure takes the blood through the inferior vena cava
directly to the pulmonary arteries with the superior vena cava blood. All the blood then goes to the lungs for
oxygenation before going to the heart for pumping to the body.