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NBME 20 Answers

nbme20/Block 4/Question#8
A 58-year-old man is brought to the emergency ...

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 +11  upvote downvote
submitted by xxabi(195),

I was under the impression that this was an aortic dissection, due to "severe chest pain" as well as the false lumen in the aorta. And HTN is the #1 risk factor for aortic dissection. Someone correct me if i'm wrong, but I think this is aortic dissection rather than aortic aneurysm.

chefcurry  I believe so, FA 2018 pg 299 +3  
ergogenic22  It is dissection "extra lumen in the media of the proximal aorta" = "a longitudinal intimal (tunica intima) tear with dissection of blood through the media of the aortic wall" ... answer is still hypertension +1  
breis  FA 2019: 301 +  
pg32  First Aid says that aortic dissection causes widening of the mediastinum and is due to an intimal tear, so I thought it wasn't an aortic dissection. Can anyone help me understand why First Aid was wrong in this case? Thanks! +3  
nephroguy  @pg32 The question stems states that there is no widening of the Aorta, not the mediastinum. Widening of the mediastinum is seen in dissection while widening of the aorta is seen in aneurysm. Also the intimal tear creates a false lumen between the intima and media. Hope that helps! +3  

 +3  upvote downvote
submitted by step1soon(24),

Widening of the = ANEURYSM!

Extra lumen in media of aorta = DISSECTION

THIS pt has an aortic dissection

1 RISK factor is Hypertension!!

(syphillus would be correct of the pt had an aneurysm but HIS CHEST X-RAY DO NOT show widening of the aorta)

gabriela  @step1soon were you upset when you wrote this comment? lol +  

This is not an aneurysm, which is what makes this question so weird: "x-rays of the chest do not show widening." My understanding was that dissections usually occur in the picture of aneurysm, especially due to hypertension. However, perhaps that's not the case, particularly in these Stanford Type A dissections? The picture in FA sure makes it look like a widened aorta (aneurysm) with a dissection...

 +0  upvote downvote
submitted by eacv(18),

This is an AORTIC DISSECTION: No. 1 RF is HTA, intimal tear forming a false lumen and the pain sudden onset radiates to the back.

Robbin's: The two most important causes of aortic aneurysms are atherosclerosis and hypertension. Atherosclerosis is the more dominant factor in abdominal aortic aneurysms, while hypertension is associated with ascending aortic aneurysms.

 -1  upvote downvote
submitted by step420(29),

Hypertension can lead to aneurysms like in this patient. Not syphilis because not thoracic aorta.

 -5  upvote downvote
submitted by haliburton(171),

FA 2017: 3° syphilis disrupts the vasa vasorum of the aorta with consequent atrophy of vessel wall and dilatation of aorta and valve ring. May see calcification of aortic root, ascending aortic arch, and thoracic aorta. Leads to “tree bark” appearance of aorta. Can result in aneurysm of ascending aorta or aortic arch, aortic insufficiency.

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