About Hypoplastic Left Heart Syndrome

Hypoplastic Left Heart Syndrome (HLHS) is a rare and complex heart defect present at birth, This congenital heart defect (CHD) - is usually discovered during ultrasounds early in the pregnancy. During a 20 week ultrasound, our doctors said they needed a better look at the baby's heart and referred us to the Danbury Hospital. (We went through the same drill with Cambria so we weren't too worried.) But it was this hospital heart ultrasound where Declan's received his diagnosis.

We learned that HLHS is basically a severely underdeveloped left heart.  Normally, in a healthy heart, the right side pumps blood to the lungs and the left side pumps the oxygenated blood to the body -the sides are separated and the oxygenated and deoxygenated blood doesn't mix.  But once born, the left side of the heart can't effectively pump blood through the body, so the right side must pump blood both into the lungs and to the rest of the body.

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As you can see from the diagram, with HLHS, Declan's left ventricle would be too small and underdeveloped to properly pump and supply his body with oxygenated blood. Additionally, in Declan's case the Aorta is severely underdeveloped which would further limit blood supply to his body. Usually the Aortic valve and Mitral valve are also underdeveloped.  What does this mean? If left untreated, the condition is fatal within the first few days of life. While Declan hangs out inside Tammy, he gets his oxygen through the placenta, so it isn't too much of an issue. Without getting into too much detail, while in utero, there are also valves that are open that allows blood to flow back and forth between the chambers. These valves close within the first few days of birth and that's when the problems would start if left untreated. The underdeveloped left side and underdeveloped Aorta could not adequately supply the body with oxygenated blood. The condition was fatal until a series of 3 operations were developed in the late 1980's.

The first surgery, often called the Norwood procedure occurs within the first few days of birth. The second surgery, or the Glen procedure usually takes place between 4 to 6 months, and the last surgery is called the Fontan. I have some links below, but the end goal after the Fontan is to have the deoxygenated blood flow passively back to the lungs and the right side of the heart replumbed to pump the oxygen rich blood to the body. 

The surgeries do not "cure" Declan, but they will ideally allow him to function with "half a heart". He may need a heart transplant or two as some point down the road, we just don't know how he will react to everything. He wont be an Olympian, or an NFL or NBA player, but he will be our star. Our love for him will be greater than any fanfare.

Some helpful links and videos:

Children's Hospital of Philadelphia HLHS
Stage One Surgery: Norwood
Sage Two Surgery: Glen
Stage Three Surgery: Fontan