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  #1  
Old 11-25-2011
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Stethoscope The cause of PreSystolic Sound?

72 yr Caucasian male with pre-systolic sound immediately precedes S1 on auscultation in left lateral position. His bp 150/90 hr is 74. h/o of hypertension and evidence of extensive calcinosis around mitral and aortic valve on x ray.
What is the cause of extra sound?

A. increased flow across aortic valve
B. restricted motion of aortic valve
C. restricted motion of mitral valve
D. increased stiffness of LV wall
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I would go with D
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yup the answer is d
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Old 11-25-2011
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D.increased stiffness of LV wall he is old
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the answer is D
I did it today but I did not know the correct answer!
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guys in the Mitral stenosis also there is Pre systolic accentuation sound just before S1 so can someone explain why its not C
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Old 11-25-2011
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Hey I think because there is evidence of aortic stenosis, meaning that the ventricle had to work against more pressure and therefore maby hypertrophied. Then the atrium had to work against more resistance and then u can hear the atrial kick (just before S1).
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Old 11-26-2011
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presystolic accentuation in ms is also due 2 atrial kick (S4) ....
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Quote:
Originally Posted by rose View Post
the answer is D
I did it today but I did not know the correct answer!
which q bank u did
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Old 11-26-2011
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Quote:
Originally Posted by mohitkmc View Post
guys in the Mitral stenosis also there is Pre systolic accentuation sound just before S1 so can someone explain why its not C
I guess the question stem mentioned hypertension and calcification of aortic valves, so it acts as a clue to indicate left ventricular hypertrophy because it has to contract intensively to overcome the high pressure at and after aortic valves in order to maintain a normal blood pressure. So in a long run, left ventricular wall gets stiff. If choosing c, I think you didn't take high blood pressure into account, so that's not the best answer choice.

Hope my explanation helps a little bit.
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Old 11-26-2011
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I think the correct answer is D:
The patient clearly has history of uncontrolled HTN which means that he has some LVH or at least stiff LV and diastolic dysfunction which usually produces a presystolic atrial sound called S4 or as we say atrial gallop due to atrial contraction against high diastolic pressure or stiff ventricle
If this patient has high flow across aortic valve (choice A) there should have been a systolic murmur which is not mentioned. If there is a restricted aortic valve opening (choice V) there should be decreased S2 intensity, some reversed S2 splitting in addition to some systolic murmur in some cases. Finally if the mitral valve is restricted (choice A) as in MS the first sound itself will be accentuated together with a post S2 opening snap sound and the presystolic accentuation that is before S1 is a part of the rumbling murmur that continues from early diastole and accentuates in the late diastole (pre systole) if there us no AF.
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Old 11-26-2011
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Quote:
Originally Posted by alaahoda2001 View Post
I think the correct answer is D:
The patient clearly has history of uncontrolled HTN which means that he has some LVH or at least stiff LV and diastolic dysfunction which usually produces a presystolic atrial sound called S4 or as we say atrial gallop due to atrial contraction against high diastolic pressure or stiff ventricle
If this patient has high flow across aortic valve (choice A) there should have been a systolic murmur which is not mentioned. If there is a restricted aortic valve opening (choice V) there should be decreased S2 intensity, some reversed S2 splitting in addition to some systolic murmur in some cases. Finally if the mitral valve is restricted (choice A) as in MS the first sound itself will be accentuated together with a post S2 opening snap sound and the presystolic accentuation that is before S1 is a part of the rumbling murmur that continues from early diastole and accentuates in the late diastole (pre systole) if there us no AF.
I'm confused why, in the situation of mitral valve restriction, S1 is accentuated?
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Old 11-26-2011
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Quote:
Originally Posted by belindalimm View Post
I'm confused why, in the situation of mitral valve restriction, S1 is accentuated?
In case of mitral stenosis, the shape of the mitral valve leaflets and the sub valvular apparatus makes it that mitral valve shuts very forcefully and that is why S1 becomes accentuated
Imagine that the mitral valve leaflet itself is still pliable but the commodores are closed by rheumatic fever --> button hall I.e. Stenosis --> blood backs up in the LA --> high LA pressure --> pushes the MV to open suddenly and streched it so much with a sudden hilt die to the stenosis (opening snap) --> blood flows from LA to LV very fast across a narrow opening --> murmur --> left atrial contraction --> presystolic murmur accentuation --> finally the streched valve gets to close and because of the stretch it the closure happens forcefully --> loud S1
Another factor that helps that is the affection of the chords +\- the papillary muscles --> streched +\- calcified cords --> limited mobility --> streched valve while open --> and so the forceful shutting
the affection of the cords might later also cause associated mitral regurgitation
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