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Current time:0:00Total duration:4:42

Video transcript

in cyanotic heart diseases usually we're talking about a right-to-left direction of shunting so the bluer less oxygenated blood on the right side is going to the left side and out to the body it's why we become blue or cyanotic now the counterpart to cyanotic diseases are the ones that are not cyanotic obviously so they the shunting in these situations go from left to right so we have the red blood going into the deoxygenated part all we get is blood going to the lungs having a higher content of oxygen this doesn't turn anybody blue so they're not cyanotic AHA but there's a catch there's something that can happen later on this child's life that suddenly turn them cyanotic an example I want to use to talk about all this is a heart disease called coarctation of the aorta CO arc tation it's a fancy word for restriction coarctation of the aorta so like I said it's a restriction of the aorta it looks like this so instead of our nice big a order that we had before in this case the order comes down here and whoop there's a little cowork there right there actually could be anywhere but that's one of the most common places to have it so then the rest of it goes on so this little squeeze here creates a lot of resistance resistance because there's a lot of blood flowing through the aorta at any second and to have this bottleneck here creates a lot of resistance which again increases the pressure so now we have the left side having even more pressure than before and confrontation can be its own isolated defect for sometimes it also involves a VSD a ventricular septal defect that just means a hole between the two ventricles so here we have our B s D so if we have both just to drive home the idea of their shunt think about so the blood going into the aorta has a lot of resistance you then it's going to back up right into the VSD so the shunting goes this way so let's say we don't fix this color no surgery this child grows up I mean they'll have kind of compromised flow of blood into their system but they can survive now the while we have left or right shunting we can live with that but imagine what happens to a muscle to this specifically to the right ventricle muscle that is receiving more volume of blood than it's used to usually there's no shunting here and the right ventricle does its job by coming to the lungs but with all this shunting we have all this extra volume of blood to the lungs day in and day out any time you exercise a muscle too much it becomes thicker and stronger so imagine this right ventricle is thickening it's learning to work harder and harder just going to draw it in here to drive home the point so now I have this thick wall of the right ventricle now remember that the left and right ventricles squeeze together at the same time and usually the left ventricle is so strong that we get blood this way and then one day finally the right ventricle has grown big enough it's going to give one big squeeze and it's going to overpower the left ventricle and the blood is suddenly going to go this way so instead of our right left-to-right shunt now we're going right to left because the right ventricle now has the greater power this is a phenomena of the reversal of the shunt now going right to left because the right ventricle has grown so big so we call eisah monger it's a minger depending on how you want to pronounce it and this usually happens around age five or six dippity on the child and what our actual structure looks like and I used blue here because suddenly our shunt is going from deoxygenated blood to oxygenated now the mixing happens the other way and now the child is cyanotic I just threw in the coart here to drive home the point but even this child just had a VSD it would be the same thing initially we would have left or right to going this way with a big left ventricle and eventually it will reverse so as a mango just refers to as reversal of the shunt so just because you're born with a left-to-right shunt doesn't mean you get out of being cyanotic forever there's always the potential to reverse the shunt end up having cyanotic heart disease