cardio question plz help on heart sound with graph

[sadaca]

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hey guys, could someone plz explain this question ? I picked 2nd heart sound b/c it looks like the spot where AV would close but the answer is 3rd heart sound, mid diastolic. How are we supposed to get that from just the graph?

really appreciate it

 

[sadaca]

My bad- the question is asking what does the point on the graph represent and it lists : 1st heart sound 2nd 3rd and 4th. Ans is : 3rd heart sound

 

[deleted500612]

Well, if the probe is measuring flow across the mitral valve, the peaks on the graph will represent ventricular filling in diastole. S1 and S2 mark the start and finish of systole respectively, so we can rule out S1 and S2 right off the bat. I think the initial peak represents blood flow from passive ventricular filling, while the second peak denotes blood filling from left atrial contraction. An S3 is heard during passive filling in mid-diastole, while S4 is heard during atrial contraction in late-diastole, so the sound most closely related to the arrow would indeed be S3. Also the description of the patient's symptoms is consistent with CHF which also suggests S3. Hope this helps.

 

[haloschief]

This might help:

Between S1 and S2 mitral valve is closed so no flow. Notice that when you hear S2 (Aortic valve closure), the mitral valve doesn't open yet since LV pressure is still high and in process of relaxing so there is a delay between aortic valve closure and mitral valve opening. Therefore, there is no flow across mitral valve at S2 either. Eliminate S1 and S2 based on that.

The first peak in your picture correlates to mitral valve opening. Peak is when flow is greatest so when you hear S3 then slowly decreases but there is still flow. 2nd smaller peak is atrial contraction sending any left over blood to LV so that is correlated with S4.

 

[ddw2013]

I also did this UWSA q yesterday. but haven't check answer yet.
I thought this pt has MR because he has a second small wave. So MR-->dilated cardiomyopathy or CHF which will have 3rd heart sound.
The 3rd heart sound is on early phase of diastole phase due to rapid filling which is pointed (max blood flow). The second wave I thought was the regurgitation.
If it is really MR, the second heart sound should be somewhere between 1st and 2nd wave.
Again I haven't check answer yet so I'm not sure my understanding is correct.

 

[sadaca]

Thank you guys so so much. It was so helpful. I guess the trick was that they said mitral valve flow, so that eliminates s1 and s2 b/c in those MV is closed. And s3 is early diastolic when MV opens and S4 is late diastolic right before MV closes. The graph threw me off b/c I was comparing to the one in FA, the one that Halochief posted above. Because if you look at that and see the peak it makes you think its AV closing, right? I get it otherwise

 

[DeeJay2728]

So if the arrow were pointing to the smaller peak, would that be S4?