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Video transcript

- [Voiceover] Now this time in TAPVR, we're dealing with a pulmonary veins that happens to be the one thing I didn't draw. But let's label what I did draw. We have the right atrium receiving blood from the body going to the right ventricle pumping it to the lungs through the pulmonary arteries. And then the pulmonary veins are the things that give blood back to the atrium on the left side from the lungs. See pulmonary meaning it comes from the lungs and vein means it's going back to the heart instead of artery which is away from the heart. So the lungs giving oxygen and red blood back to the left atrium. Those are our pulmonary veins and we have the left ventricle which pumps it to the body. The thing with TAPVR is instead of it being plugged over here where it's supposed to be, our pulmonary veins are plugged over here into the right ventricle. I'm going to draw two here coming from the left and right lungs. So the right ventricle usually receives blue deoxygenated blood from the body. But now we've red blood from the lungs coming by here too. So, let's see there's deoxygenated blue blood from the veins and red blood. So here our right atrium's receiving this mixture. Again this purplish kind of blood is floating around in our right atrium. And from there the rest of the circuit is the same. It goes to the right ventricle. It goes to the lungs. So again we have purple blood going out to our lungs. But from there the blood picks up enough oxygen to become red again and then comes back through these misplugged pulmonary veins right here. So as you can see, there's nothing going on on the left side. It's as if this chamber is sealed off. There's nothing coming back into the left atrium. and therefore, this is all empty. That means there's nothing going on in the aorta. There's no blood being pumped to the body, As you know, that's not compatible with life, so usually TAPVR also involves ASD. So Atrial Septal, which is the wall between them, Septal Defect. So thankfully, we have a hole between the left and right atria here, a little hole, So that our purple blood can go this way and the left atrium will be filled from the right side with purple blood. And now this purple blood can then go into the left ventricle and out through the aorta into the body. Because without this little hole here, then we just have deoxygenated blood coming from the body, mixing there with the red blood from the lungs into purple blood going back to the lungs and coming back as red blood. And then we have again, we have this closed circuit. It has nothing to do with the body and we can't survive without blood going into our aorta, into the body. So this closed system has to be opened and that's why we have the ASD here, to allow the mixed blood into the left side so we can survive. Usually, this also involves right ventricular hypertrophy, because look, it's doing twice the work it's used to. There's just an overwhelming amount of volume of blood going to the right side. So this increased workload will give us right ventricular hypertrophy as well. And this, again, needs surgical correction to replug the pulmonary veins back where they belong. So, just remember these misplaced pulmonary veins when you think of TAPVR