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Video transcript

- So when most people think of the heart, they think about something like this. Or love or Valentine's Day, and that's all great. But what if you're a little more medically inclined, or scientifically inclined? Well then maybe you think about something such as the heart sounds, or lub dub. And I'm gonna give you a second to put in your headphones because those will actually help you hear these sounds better during the video. (heart sounds) And so you can hear those normal heart sounds. But what happens if maybe, when you visited your cardiologist, he or she heard something extra while they were listening to your heart? Well maybe they told you that you have a murmur. And so keep those headphones in because I'm gonna play you one of the more common murmurs. (abnormal heart sounds) You'll notice that you actually hear the lub and the dub, but in the middle you actually hear this whishing or blowing sound. So what's a murmur? Well, it's really pretty simple. It's actually just the sound of turbulent blood flow. And when we say turbulent, all we mean is the same thing that we mean when we talk about a turbulent plane ride, rough. So it's the sound of rough blood flow through a cardiac structure. And in particular, we're gonna be talking about the valves. And so this is a good time to remind you that we have four valves in the heart. And those are the mitral, the tricuspid, the aortic, and the pulmonic. So when someone's told that they have a murmur, they automatically freak out. And that shouldn't always be the case because murmurs can actually be normal, or abnormal. And so normal murmurs are also called functional, or innocent murmurs. And abnormal murmurs are also called pathologic murmurs. So you may be thinking, well how can a murmur be innocent or normal? Well, let me draw you a picture here, and see if we can help explain this. So here we're just gonna draw any normal valve. And so this would be a valve like the tricuspid valve or the aortic value or even the pulmonic valve. Those all have three cusps, and so this is a trileaflet valve. And so in a normal, or functional murmur, you simply have an increase in flow. And when we say flow here, we mean blood flow. And so you really just have a lot of blood flow through this normal valve. And that can actually cause a little bit of turbulence and lead to a murmur. But the important point is that this valve is absolutely normal. Now in the abnormal murmurs, the valve is actually dysfunctional. And that is what's causing the turbulent blood flow and murmur. And so instead of it being nice like this, well maybe you have a little situation like this. Or maybe some of these edges are scarred up or old, and not working correctly. And so now either not enough blood can get through, or blood can actually leak back when it's not supposed to. And so again, it's really important to know that in this case, the valve is what is abnormal. And so in abnormal murmurs, the valve can be dysfunctional in one of two ways. And the first is that the valve can be stenotic, where you can have a situation of stenosis. And the other is called regurgitation. And you'll also see this as insufficient. And so the way I like to think about this, because I always used to get them confused, is by using a typical high school. And so here we're gonna draw the halls of a high school. And we're gonna use double doors as our valve. And so when the kids are still in class and the bell hasn't rung yet, these doors are closed. And no one's going in or out of them. Now when the bell rings, students push open the door, and if everything's working normally, these doors open very wide, just about all the way. And all of the students can get through, and they do this in a pretty orderly fashion, and everything's kinda smooth, and everyone gets to go home. But what if these doors were a little bit sticky, or maybe the hinges hadn't been greased in a while? Well now you get a situation like this. And so now when students try and get out, they're kinda forced from all over to get through this tighter space, and not as many of them can get out. And so there's all this pushing and shoving, and this is the picture of stenosis. In this case, we have a stenotic door, or in the case of the heart, we would have a stenotic valve. And so let me go ahead and label the normal conditions. So this is normally how we want the door to open. So this is normal open. And then this is normally how we want the door to close. So this is normal closed. Now let's talk about the same thing for regurgitation, but in this case, we're gonna start with the normal open scenario. Se let me draw these hallways again. So in the normal open situation, remember these doors are all the way open. And we're gonna assume this is a little bit later in time, and so that the kids are actually a little bit further ahead here. And so the doors are getting ready to close. Now once those kids have left, we need the doors to close properly so that no one else can get back in. And so normally these doors will close, and no one can get back in, even if they'd want to. And you'll see these are kinda like students coming back for after school activities, but they're not gonna be allowed in because the doors are closed. Now what happens if these doors become a little floppy? Well now, let's say maybe one comes back to normal, but the other one overshoots or something like that? And the details of that are not important, but what is important is that you now have this little pathway through which students can kinda get back through, but not many, and there's still some pushing and shoving. And so this is the case of regurgitation. And then we'll go ahead and label the normals again. And so this is normal closed. And this is normal open. And so what you really need to remember from this, because it'll help so much when you're trying to remember the different valvular diseases down the road is that stenosis is a problem with opening. So this is an opening problem. The valve, for some reason or another, is stenotic, and it can't open enough, meaning not enough blood can get out. And so again, this is an opening problem. Now regurgitation is kind of the opposite. And so this is a closing problem. Now the valve, for whatever reason, is regurgitant, and can't close all the way. And so now this can cause back leak of blood, and again, this is a closing problem. So you can imagine that if we're having problems opening valves or closing them in the heart, that we can actually get some signs and symptoms, such as fatigue, and then you can see this guy laying down and not feeling so well. Shortness of breath, and you'll see I've drawn you a little pair of lungs here that's just a little too short. And finally swelling, and this is usually swelling of the extremities, such as the feet. And so these are some general signs and symptoms that would be associated with valvular heart disease.