need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (โ€œpredict me!โ€)

NBME 20 Answers

nbme20/Block 3/Question#12 (reveal difficulty score)
A 46-year-old man has dyspnea, orthopnea, and ...
Mitral regurgitation ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags: DDX murmur

 Login (or register) to see more


 +2  upvote downvote
submitted by โˆ—breis(56)
get full access to all contentpick a username

Patient has Midsystolic murmur heard at the cardiac apex. there is also a LEFT ATRIAL abnormality. Echo shows LEFT ATRIUM is enlarged.

Mid systolic... enlarged left atrium...

Best choice: Mitral Regurg

get full access to all contentpick a username
hpsbwz  Why is it regurg instead of stenosis? +3
minhphuongpnt07  Vague question requires a lot clinical reasoning. mitral regurgitation: holosystolic murmur( this cv: midsystolic), enlarged LA, LV Mitral stenosis: diastolic murmur, enlarged LA, normal LV. only best explanation I can think of: early stage Mitral regur, that's why the murmur is not holosystolic but midsystolic and LV still adequately handle the situation +4
dickass  @hpsbwz it's regurgitation because the murmur is SYSTOLIC, when the mitral valve is not supposed to make any sound. mitral valve leaks in systole, which causes blood to back up, which causes the left atrium to work harder and eventually hypertrophy. Mitral stenosis would be a DIASTOLIC sound, which is when the left atrium normally contracts. +9
themangobandit  I'm still confused as to why mitral regurg has an enlarged left atrium. Are we supposed to think that it was mitral stenosis for a time, the high LA pressure led to hypertrophy, and then became mitral regurg? That's how it works in rheumatic fever, right? +
shapeshifter51  I agree that mitral regurgitation is a holosystolic murmur heard best heard over the apex. However, with the murmur being found in the mitral valve area of auscultation it was the only answer choice that could result in LA enlargement and normal LV. Ruled out mitral valve stenosis since it is a diastolic murmur. +1
weenathon  @themangobandit I believe mitral regurg could cause an enlarged left atrium from the increased amount of blood flooding back into the left atrium with each systole causing increased pressure on the wall. +
rockodude  why is LV size normal? doesnt cause MR cause increased preload and overload over time leading to enlarged LV? +



Must-See Comments from nbme20

amorah on Cytomegalovirus infection
masonkingcobra on Contact with parakeets
hayayah on Capillary hydrostatic: increased; ...
hayayah on X chromosome-linked isoenzymes
medbitch94 on Mannose 6-phosphate
hello on Capillary hydrostatic: increased; ...
hayayah on Osteoblasts
imgdoc on Hypophosphatemia
hayayah on Missense
celeste on 50%
justgettinby on Omeprazole
andrewk1 on Cold, dry air
yotsubato on Jugular venous pressure of 12 mm Hg
strugglebus on Drug effect

search for anything NEW!