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nbme24/Block 4/Question#38

A 33-year-old woman at 34 weeks' gestation has a ...

Stroke volume

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Would've been nice if they told you "2nd intercostal space" on left or right...smh





 +6  upvote downvote
submitted by seagull(433),

"Blood flow to various organs increases during pregnancy to meet the increased metabolic needs of tissues. Thus, venous return and cardiac output increases dramatically during pregnancy. Cardiac output gradually increases during the first 2 trimesters with the largest increase occurring by 16 weeks of gestation.3 The increase in cardiac output is well established by 5 weeks of gestation and increases to 50% above prepregnancy levels by 16 to 20 weeks of gestation. The rise in cardiac output typically plateaus after 20 weeks of gestation and remains elevated until term. The increases in cardiac output are associated with significant increases in stroke volume and heart rate (HR)"

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3802121/





 +2  upvote downvote
submitted by m-ice(124),

A soft systolic murmur is common in many pregnant women due to a high volume of flow (increased cardiac output). The murmur tends to go away within a few weeks of delivery once the cardiac output is closer to baseline.





 +1  upvote downvote
submitted by usmle11a(11),

my way was

SV =EDV-ESV

EDV increases in pregnancy due to an increase in plasma volume





 +0  upvote downvote
submitted by step420(18),

I have a question: Since CO = SV * HR, and in pregnancy, women have an increased basal HR, why can't the answer be Pulse?

home_run_ball  I don't think HR would explain the grade 2/6 murmur, but SV would +1  




 +0  upvote downvote
submitted by neonem(263),

My best guess is that this patient has a bicuspid aortic valve and has a murmur due to increased volume overload from the pregnancy.

charcot_bouchard  Can be congenital mild Tricuspid stenosis also. it also exaggerate during preg +  
wowo  probably just a flow murmur, https://acpinternist.org/weekly/archives/2017/05/16/3.htm +1  
noplanb  Wouldn't Tricuspid stenosis be a systolic murmur? +  
noplanb  I mean diastolic* +  




p 619 FA 2019 - physiologic changes in pregnancy

incr CO, anemia, hypercoagulability, hyperventilation, incr lipoylsis and fat utilization to preserve glucose and AAs for the baby