Tuesday, April 7, 2015

Terminology Tuesday: TAPVR

While this isn't necessarily arthritis related, it's obviously weighing heavily on my mind with my newborn nephew facing open heart surgery.

Total Anomalous Pumonary Venous Return (TAPVR) is a kind of Congenital Heart Defect (CHD) where the heart doesn't connect to itself correctly. In fact, it's listed as a Critical CHD, which means extra bad news.

It means he's special medically just like me and his momma though - one out of 7200 babies every year is born with a CCHD in the US. That's 1 in 4 of the 1 in 100 born with a CHD, or 1 in 400 children. TAPVR specific rates aren't available, but would be much smaller due to how many CCHDs there are.

To understand it, we're gonna need a quick rundown on how the heart works. Heads up for my boss for running through this with me last week (and to the CDC for having the best site). Can I just say again how much I love pediatric docs?

Blood that has run through the body loses oxygen. That's why our veins are blue instead of red - the blood inside has lost oxygen. That blood has to come back to the heart to get oxygen again, and it does so through the superior and inferior vena cava.

The right atrium, where the blood enters the heart, acts like a mini reservoir in that blood collects there until it is pushed down through the tricuspid valve when the heart beats. It goes into the right ventricle and, when the heart beats, it gets pushed into the lungs via the pulmonary valve and main pulmonary artery.

The blood gets oxygen in the lungs and then comes back into the heart through the left atrium. Just like the right, the left atrium acts as a holding space until the heart beats and blood is pushed through the mitral valve into the left ventricle. The muscle here has to be very strong, because when the heart beats again, the blood has to go through the aortic valve and aorta to go out into the rest of the body.

If that doesn't help, maybe this video will:

Got it? Kinda? Good!

In someone with TAPVR, the blood going out to the body carrying oxygen isn't going out the right way.

As we can see in this picture, the blood with and without oxygen is all mixing together. Here's what's going on:

The unoxygenated blood comes back to the heart like normal and even goes out the the lungs like normal. However, the oxygen-rich blood coming back from the lungs has a problem.

Sam's heart isn't set up like a normal heart. TAPVR means that the pulmonary veins aren't connected in the right spot. Instead of coming to the left atrium, the oxygenated blood goes back to the right atrium and starts the process again. The only reason Sam is getting any oxygen to his body is because there is also a small hole between both atriums, allowing both oxygen-rich and unoxygenated blood into the left atrium.

The blood going to his body isn't oxygen rich and that causes problems.

There are a few types of TAPVR. Sam's is infracardiac, meaning:
the pulmonary veins come together and form abnormal connections below the heart. A mixture of oxygen-poor blood and oxygen-rich blood returns to the right atrium from the veins of the liver and the inferior vena cava, which is the main blood vessel that brings oxygen-poor blood from the lower part of the body to the heart. (what up CDC)
The only way to correct this is to have open heart surgery. If you want to see what the surgery looks like, you can watch the graphic video here. It's upsetting, so if you're emotionally invested in this baby boy, stay away from the link or you'll wind up in a puddle like me.

With it being a CCHD, he may need further care. Some kids need more surgeries. If things go really well, he'll have to visit numerous specialists often for a long while.

This is not okay. No child should have to go through this.

No comments:

Post a Comment