I can’t help but constantly think about Hypoplastic Left Heart Syndrome (HLHS) and the more I want to understand it. A lot of people ask “what is it?” and I have usually just pointed them to the wiki page although it’s sometimes really hard to just absorb the information that’s there so I thought to myself maybe I can try and explain what I’ve taken the time to try and understand. (I add this comment after getting half way though this… I think I ended up getting into too much detail! :-/ I’ve only tried to consolidate all the information I’ve been reading about into somewhat of a summary)
Firstly, it’s important to know that the baby is completely fine in the womb and that the birth will be just like any other delivery; try to deliver naturally without having a C-Section nor does mom need to be induced for any special reason.
Secondly, even thought the baby has HLHS and fine in mom’s womb, HLHS becomes a concern for baby’s health as soon as he/she is born because the baby no longer has mom to support his/her circulation. How does mom support the circulation while the baby is in the womb? The placenta transfers nutrients and oxygen from mom to the fetus transfers waste products and carbon dioxide back from baby to mom.
In the above diagrams you can see that the umbilical cord actually has 2 arteries and 1 vein. A diagram of the heart like the ones above usually has the “left” and “right” reversed for viewing. Sorry I had to include 2 but to me it was hard to visualize with just the one. The blood flow as follows:
- Oxygenated blood enters the umbilical vein from the placenta
- Enters ductus venosus
- Passes through inferior venacava
- Enters the right atrium
- Enters the foramen ovale
- Goes to the left atrium
- Passes through left ventricle
- Flows to ascending aorta to supply nourishment to the brain and upper extremeties
- Enters superior vena cava
- Goes to right atrium
- Enters the right ventricle
- Enters pulmonary artery with some blood going to the lungs tosupply oxygen and nourishment
- Flows to ductus arteriosus
- Enters descending aorta (some blood going to the lower extremeties)
- Enters hypogastric arteries
- Goes back to the placenta
So you can see that mom is able to provide everything baby needs while in the womb through the placenta. Amazing!
Other key points to note:
- The blood is mixed blood during the time the baby is in the womb.
- The ductus arteriosus is open (“patent”, and often referred to as the PDA) allowing some blood flow in essence to bypass the left side of the heart completely.
- The foramen ovale, an opening between the left and right atrium also allows some blood flow to bypass the left side of the heart completely.
A Hypoplastic Left Heart:
Looking at the above comparisons, even though the left side of the heart is absent/underdeveloped and with mom providing the oxygenated blood through the placenta and with the foramen ovale present and the patent (open) ductus arteriosus, I now understand why the left side of the heart isn’t really a concern in the womb…
Within minutes or up to a few days after birth, the patent (open) ductus arteriosus (PDA) as well as the foramen ovale is supposed to close as part of the normal changes occurring in the baby’s circulation.
So now that these two ‘bypass-the-left-side-of-the-heart’ openings are closing, this is when the problems begin for the HLHS baby especially with the PDA possibly closing within minutes of birth. A drug called prostaglandin is given to the baby as soon as possible when the baby is born to keep the ductus arteriosus open so the baby still has mixed blood in his/her circulatory system until the 1st stage of the 3-stage Norwood surgery can be arranged. This is usually done within 3-7 days. The Norwood 3-stage operation is not a cure for this congenital heart defect but a reconstruction of the heart so that the 2 chambers of the right side of the heart are able to do the work of 4. God has given surgeons a gift of being able to perform these operations and I did finally find and watch one of the surgeries on YouTube…….. Simply amazing.
One thing I must pray hard about is whether I should cut the umbilical cord….
I’ll write about the Norwood procedure another night, it’s already 115am here and I do have to return to work in the morning (return meaning I’ll be working remotely since I brought my PC & laptop with me but spending my time with computers instead of my family :()
On another note, the heartbeat sound I could hear last night I now know is the dryer people are using… someone just came to put a load into the dryer…
Leave a Reply