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Current time:0:00Total duration:12:07

Systolic murmurs, diastolic murmurs, and extra heart sounds - Part 1

Video transcript

go ahead and put in your headphones for a second cuz I really want you to get the full effect of these murmurs here you go [Music] [Music] so I was pretty much a whirlwind of five pretty common murmurs and some extra heart sounds and so if that really confused you that's okay we're gonna go through all the mechanisms of these murmurs and I'm gonna have you understanding it in no time so it's a quick review we have s1 and s2 and I'm gonna write s one over here again because remember this is a cycle and so in between s 1 and s 2 we have systole and between s 2 and s 1 we have diastole and if you remember the s-1 and the s2 are actually caused by closing of the valves for s1 specifically the closing of the mitral and the tricuspid for s2 specifically the closing of the aortic and pulmonic valves and these are all abbreviated here now murmurs can occur between s1 and s2 and these would be systolic murmurs and these would be things like a or texts enosis or pulmonic stenosis mitral regurgitation or tricuspid regurgitation and one other thing that doesn't necessarily cause a murmur but can be accompanied by mitral regurgitation would be something like mitral valve prolapse and so the ones that we're going to talk about today are going to be the left-sided valvular conditions so the aortic stenosis and the mitral regurgitation as well as the mitral valve prolapse I just realized that I made that prolate and so we're gonna fix that now for diastolic murmurs meaning they occur between s2 and s1 these are going to be a or decree Gurjit ation or pulmonic regurgitation and mitral stenosis and tricuspid stenosis and remember the only way on arriving at these names and when these murmurs occur is based on which valves should be open or which valve should be closed during systole and diastole and so the ones that we're gonna really discuss here are going to be a or decree Gurjit ation and mitral stenosis and again you'll notice these are the left-sided valves and we're doing this because the left-sided valve problems are generally much more common than the right-sided valve problems so now that we've kind of categorized these into systolic or diastolic murmurs two questions that are going to become important are where do you hear the murmur most loudly and what's the shape of the murmur and we're going to explain these as we go through each murmur so since location is a pretty big concept I want to go over the four places that we auscultate or listen with our stethoscope so one of them is here you'll see I'm coloring this in and this is in the second space in between ribs also known as the second intercostal space and this is the aortic area this is also called the right upper sternal border on the other side in the same intercostal space or space in between ribs we have the pulmonic area and this is also called the left upper sternal border then in the fourth intercostal space we have the tricuspid area and finally in the fifth intercostal space but in what's called the midclavicular line meaning if you drew a line in the middle of the clavicle all the way down it would intersect with this point in the fifth intercostal space this is the mitral area and the mitral area is also called the apex and the reason why we listen in these different positions is because we're actually listening where the blood is expected to travel as it goes through the valve in question so let's talk about a or text enosis and what I'm going to do is I'm going to take you through the progression of this murmur from s1 to s2 in terms of what's actually happening with the valve and with the heart muscle contracting and so we're gonna start off with s1 and so if you remember s1 is the closing of this mitral valve and so let's say that this is closed and so that closing is gonna cause what we hear as s1 now when that closes the heart actually begins to contract but it's contracting against a closed a or take valve and so this valve at this point is closed and so that's the reason that an aortic stenosis murmur actually doesn't start with s1 there's actually a small time period small meeting like milliseconds in between the closing of the mitral valve and when the aortic valve actually opens and remember what gives us that murmur is turbulent flow through the aortic valve and so in the heart starts contracting and builds up enough pressure to open up this valve the leaflets of the valve will kind of accelerate upwards and when they finally pop open remember they're not opening all the way because the valve for some reason is stenotic then this will first give you what's called an ejection sound or an ejection click and that's here and we're gonna label that EC for ejection click and that's caused by these valve leaflets moving up really quick and then stopping really quick and shooting open and so when the valve first opens you're gonna get a little bit of blood flow through this valve and as the heart continues to contract more and more as shown by these arrows squeezing out more and more and more forcefully you get more and more flow and then eventually as the heart starts to relax a little bit and we're gonna now get rid of these arrows you're gonna get less and less flow and so the way that this murmur actually looks the shape of the murmur is that like we said as it contracts more forcefully you get more and more flow and the murmur becomes more and more intense and then as the ventricle starts relaxing it becomes less and less intense and so we call this a crescendo decrescendo murmur and you'll also hear people call this or refer to this as the a diamond-shaped murmur and you can kind of see that around here if you were to outline this and so aortic stenosis is called a systolic ejection murmur and that makes sense because you're rejecting blood out of the aorta and it can often have an ejection click and it's usually heard most loudly at the aortic area and so the last thing I want to tell you about this is that commonly this murmur can actually radiate to the neck or the carotid and the reason for that is that this murmur is occurring in the aorta and if you remember some of the first branches off the aorta are actually the carotid arteries and so you can hear the murmurs resonating up through the carotid arteries in the neck now a quick note and you'll notice this for all the other murmurs that we go through pulmonic stenosis which is really just the same thing as aortic stenosis but on the other side of the heart the right side is virtually the same murmur it's a systolic ejection murmur crescendo decrescendo and you can have an ejection click but this one's not going to radiate to the neck of the carotid and instead of being heard in the aortic area it's normally heard in the pulmonic area so the next murmur that i want to talk about is mitral regurgitation and remember we're still on systolic murmurs so mitral regurgitation is going to be best heard in the mitral area or apex this murmur is actually what we call a hollow systolic or a pan systolic murmur and all that means is that it lasts throughout the entirety of systole so let's start at s1 in a normal heart as one is caused by the closing of the mitral valve and that closing occurs because the pressure in the ventricle this P here is greater than the pressure in the atrium this small P here and so normally this valve would close and that would give you your s1 and in addition you have your closed a or Tec valve here but instead of closing remember we're talking about mitral regurgitation and so this is a closing problem and so as the pressure starts to build in this left ventricle but still with the aortic valve closed blood is actually getting through this valve and so that's going to cause a murmur right when s1 occurs so right as that valve tries to close a doesn't close fully and because the pressure is higher than the left ventricle down the left atrium you actually start that murmur right at s1 now as soon as the heart begins to eject blood this aortic valve opens right up and blood comes out this way but because the pressure remains higher in this ventricle then the atrium the whole time you actually get flow through this regurgitant valve throughout the entire cycle and you would think naturally that as the heart contracts harder that maybe this pressure would become bigger and the truth is that the pressure actually does become bigger but in chronic mitral regurgitation which is what we're talking about the atrium actually gets bigger or dilates and so by doing this it becomes more compliant and what that means is that it can accept the blood that's coming back into it at a lower pressure so it can accept more volume at a lower pressure and as a result that pressure in the atrium does not go up so much but because the pressure difference between the left ventricle which is really high remember that's the work force of the body and the left atrium which is pretty low because it's just receiving blood from the lungs which is a low pressure system the Jets of blood that actually come through here make a sound that to our ears doesn't change in intensity and it occurs all the way until the second heart sound when this aortic valve closes and at that point in time of millisecond or so later the mitral valve will open again and start a new diastolic cycle so as I've written here we actually call this a holo or pansystolic murmur in addition it's also referred to as a flat murmur because the intensity does not change and this murmur will actually radiate to the axilla and so if you picture this valve kind of sitting in this general area somewhere when blood flow goes back the other way it's gonna kind of be forced in the direction of this guy's armpit over here now again just to mention the right-sided valve problem tricuspid regurgitation you have the same murmur a holosystolic flat murmur but in that case you would hear it in the tricuspid area and that murmur wouldn't radiate to the axilla because the valve is in a different position