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Ventricular septal defect

An ventricular septal defect is a hole between the two ventricles of the heart. Normally this hole is present at birth but closes within a few days of life. Failure of this hole to close is called a ventricular septal defect, and usually is asymptomatic (no obvious symptoms are present). Created by Leslie Samuel.

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Video transcript

Voiceover: Oh, I could remember it as it was yesterday. My son was brought into the world. And we were all excited and there were a lot of things going on, a lot of emotions all over the place. But one of the things that I noticed, is that the nurse took him, she started to clean him off, of course, but then she did something that was extremely important. She took this little device that we call a stethoscope. One end was in her ears, and the other one went towards the chest of my little son. And she started to listen to the heartbeat. And I can imagine that she was expecting to hear something like this: (healthy heartbeat). Now because we're dealing with a newborn baby, of course the heart rate is going to be significantly faster than that. But the main thing that she's listening to is to hear that 'lub-do, lub-do, lub-do', because that tells us something about the functioning of the heart. Now, what if she were to hear something that sounded like this: (off-beat heartbeat). Oh, that doesn't sound as good as I would like it to sound. It sounds like blood is squirting into a place that it's not supposed to be going. And that's exactly what we see in babies that are born with what is called a ventricular septal defect. Ventricular septal defect. Septal defect. And what that basically is, if you break it down, a ventricular reverse to our ventricles. We have a left ventricle, and a right ventricle. Septul refers to this structure, this wall. The word septum means wall. And we have a wall between the left and right ventricle. And a defect is where we have some kind of structural abnormality. And in this case we're dealing with a hole in the wall between the left and right ventricle. And that is called a ventricular septal defect. Now, what's going to happen if an individual is born with a ventricular septal defect? Well, we're going to have blood that's going to be squirting from the left side into the right. There's not supposed to be this opening. But if there's this opening, once the ventricles contract, the blood is not only going to go to the rest of the body via this great vessel that we see here that's called the aorta, it's also going to go in through this opening to go into the right side. So we're going to get what we call a left to right shunt. In other words, blood is shunting from the left to right, where it's just squeezing through that opening. And as it's squeezing through that opening, you can imagine, okay, the blood is flowing, and it's encountering turbulence as it's going through this opening that's not supposed to be there. And that is what you hear in that when you listen with a stethoscope. And that is called a holosystolic murmur. Holosystolic murmur. Now, in terms of the location of this ventricular septal defect, it can be anywhere along this septum. And the place that we're most likely to see it, is higher up where you can see it's significantly thinner here than it is down there. And that is called my membranous... membranous septum. And the reason it's called that, when you think about a membrane, you think about something very thin, right? And this part at the top here, closer to the atria, we're going to have a thinner wall that's more membrane-like. And that's called the membranous septum. This is where we're going to see it in most cases. And then, lower down, we have the part that we call the, and you probably can guess this, muscular... muscular septum. It's much thicker. It's more muscular. And that's why we call it the muscular septum. Now, what's going to happen when we have this situation? Okay, so we mentioned that blood is going to flow from the left to the right. And of course if it flows from the left to the right, it's going to continue on with the rest of the blood to go to our lungs. And although that is a more inefficient system because we have that blood just recirculating here, as opposed to going directly to the rest of the body, it is usually going to be asymptomatic. So let's... what color should I use for that one? Let's see... I'm running out of colors. So I'm going to go back with my green and just say that it's usually asymptomatic. So we don't usually see significant problems as a result of a small ventricular septal defect. However, if it's larger, it can cause some significant problems. So in terms of treatment then, in most cases, we leave it alone, since it's going to be asymptomatic and you can live with it. The oxygen levels are adequate. So I'll put that here with asymptomatic. Oxygen levels adequate. It's not going to cause a significant loss of function. But if it's larger, so if we have a large hole in the wall, then it can be treated with surgery. And of course with surgery, the main goal is to repair that hole so that the blood no longer moves from the left side to the right side. So a ventricular septal defect is where we have a defect in the wall. A congenital, meaning the individual is born with it, hole in the wall between the left and right ventricle, causing blood to shunt from left to right. Resulting in a holosystolic murmur when you listen to it with a stethoscope. Usually in the membranous septum, but sometimes also in the muscular septum. Normally asymptomatic because the oxygen levels are adequate, and if it gets really large, then surgery might be necessary to repair that hole.