Mehl. cardio vessels: aorta Flashcards
Mehl. Aortic dissection.
As discussed above in the aortic regurg section, USMLE loves this as most common cause of AR due to retrograde propagation toward the aortic root. For example, patient with Hx of HTN, cocaine use, or a connective tissue disorder (i.e., Marfan, Ehlers-Danlos) who has a diastolic murmur, you should be thinking immediately that this is dissection.
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Mehl. Aortic dissection. CP?
Classically presents as severe upper chest pain radiating to the back between the scapulae.
Mehl. Aortic dissection…. is a term that is used on NBME exams to describe changes to the aorta in dissection
“Medial necrosis”
Mehl. Aortic dissection.
In the past, “cystic medial necrosis” used to be buzzy for dissection due to Marfan syndrome, but I haven’t seen USMLE care about this. I have, however, seen a dissection Q on NBME where it is due to hypertension, and simply “medial necrosis” is the answer.
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Mehl. Aortic dissection. As mentioned in other BS card deck, 3/4 Qs where BP is different between the arms refers to aortic dissection
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Mehl. Aortic dissection.
A Q on 2CK IM form 7 has “……” where not only is the BP different between the arms, but it’s also different between the L and R legs (i.e., L-leg BP is different from R-leg BP)àsometimes thoracic aortic dissections can anterograde propagate all the way down to the abdominal aorta.
thoracic aortic dissection
Mehl. Aortic dissection and Subclavian steal syndrome have different BP in arms.
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Mehl. Aortic dissection. You do not need to memorize these aortic aneurysm types. I’m just showing you that if the common iliacs are involved (as with left image), BP can differ as well between the legs.
Mehl. Aortic dissection. Tx for ascending aortic aneurysm (type A) ?
labetalol + surgery.
Mehl. Aortic dissection. Tx for descending aortic aneurysm (type B) ?
labetalol alone initially.
Mehl. Traumatic rupture of the aorta. Cause?
Caused by deceleration injury. Most common cause of death due to car accident or fall. Exceedingly HY on 2CK.
Mehl. MCC of death due to car accident or fall. ??
Traumatic rupture of the aorta
Mehl. Traumatic rupture of the aorta.
Will be described as patient following an MVA who has “widening of the mediastinum.” They’ll then ask for the next best step?
answer = aortic angiography (aka aortography), OR CT angiography.
Mehl. Traumatic rupture of the aorta.
New 2CK form has “CT scan of the chest” straight up as the answer, which refers to CT angiography. NBME/USMLE will not force you to choose between aortography or CT angiography; they’ll just list one.
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Mehl. Traumatic rupture of the aorta.
first-line drug in patients who have aortic dissection and traumatic rupture of the aorta??
Labetalol
Mehl. Traumatic rupture of the aorta.
Labetalol is answer on NBME even in patient who has low BP due to rupture or dissection due to the drug ̄ shearing forces. I’ve seen students get this wrong saying, “But patient has low BP though.
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Mehl. Traumatic rupture of the aorta. what comes after labetalol?
Nitroprusside
Mehl. Traumatic rupture of the aorta.
2CK Q gives “esmolol + nitroprusside” as answer to a traumatic rupture Q, but almost always, they will just want “labetalol.”
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Mehl. Traumatic rupture of the aorta. Tx? not drug
IV drug administration –> then do surgery
Emergency surgical repair is indicated following IV drug administration
Mehl. Aortic aneurysm. Can present as “visible pulsation” on USMLE.
For aortic aneurysm, they can say “visible pulsation above the manubrium,” or “pulsatile mass above the manubrium.”
Mehl. Aortic aneurysm. what pneumo presentation?
There can also be a tracheal shift. I’ve seen students select pneumothorax here. But for whatever reason you can get tracheal shift in thoracic aortic aneurysm.
Mehl. Aortic aneurysm.
For AAA, there can be “visible pulsation in the epigastrium.”
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Mehl. Aortic aneurysm. Biggest risk factor for AAA?
SMOKING
Mehl. Aortic aneurysm. Do a one-off abdominal ultrasound in ??
BOTH men and women 65+ who are ever-smokers. This screening used to be just performed on men, but now it includes women.
Mehl. Aortic aneurysm. AAA repair is indicated if the aneurysm is size? 2
> 5.5 cm
OR
the rate of change of size increase is >0.5cm/month for 6 months
Mehl. Aortic aneurysm.
This is on 2CK form, where they give a patient with a 4-cm AAA and ask why serial ultrasounds are indicated -> answer = “size of aneurysm.”
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Mehl. Aortic aneurysm. In general, perioperative MI risk is assessed using a pre-op stress test. WHAT TESTS?
2CK NBME Q has dipyridamole and thallium pharmacologic stress test as answer in patient with 6-cm AAA prior to surgery.
Mehl. Aortic aneurysm. what disease is protective?
Diabetes is protective against aneurysm. Non-enzymatic glycosylation of endothelium causes stiffening of the vascular wall.
Mehl. Aortic aneurysm. when dont do treatment?
Don’t do AAA repair on USMLE in patient who has advanced comorbidities or terminal disease, e.g., stage 4 lung cancer.
Mehl. Aortic aneurysm.
Tangential: 2CK loves “pulsatile hematoma” in the neck in trauma patients, where the answer is “endotracheal intubation.” Sounds nitpicky, but shows up repeatedly.
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Mehl. Arteriovenous fistula. Causes?
Can be idiopathic, iatrogenic (i.e., dialysis), from injury (i.e., stab wound), or caused by other disease (i.e., hereditary hemorrhagic telangiectasia or Paget disease of bone).
Mehl. Arteriovenous fistula. Similar to aortic aneurysms, AV fistulae can sometimes present with pulsatile mass, but in what locations?
in a weird location, e.g., around the left ear in patient with tinnitus (on NBME exam).
Mehl. Arteriovenous fistula. Highest yield point is they can cause ???
high-output cardiac failure. This is because blood quickly enters the venous circulation from the arterial circulation -> combo of incr. preload back to right heart + poorer arterial perfusion distal to the fistula -> compensatory incr. CO.
Mehl. Arteriovenous fistula. what murmur in the location of fistula??
AV fistulae can sometimes present with a continuous machinery murmur similar to a PDA, since blood is continuously flowing through it. They might say a continuous machinery-like murmur is auscultated in the leg at site of prior stab wound.
Mehl. Arteriovenous fistula. they can present with what pulses?
bounding pulses similar to AR
Mehl. Arteriovenous fistula.
Student says, “Well how am I supposed to know if it’s AV fistula then if it sounds like other conditions too?”àby paying attention to HY points like, “Is there lone S3 or S3/4 combo or EF >70%? Is there Hx of penetrating trauma? Or does the patient have Paget? Etc.”
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Mehl. Arteriovenous fistula.
2CK NBME Q shows you obscure angiogram of a fistula in the leg + tells you there’s a continuous machinery murmur; they ask what most likely determines prognosis in this patient??
Size of lesion.
Mehl. Arteriovenous fistula. NBME exam shows obscure image similar to above (without the arrow) + they tell you there’s continuous murmur = Size of lesion.
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Mehl. Arteriovenous fistula.
Another NBME Q gives 45-year-old male will nosebleeds since adolescence + S3 heart sound + dyspnea + they show you pic of tongue (kraujosruvos); they ask for the cause of dyspnea.
- Answer = “Pulmonary arteriovenous fistula” (leading to high-output failure); diagnosis is hereditary hemorrhagic telangiectasia. USMLE will basically always show you a pic of red dots on the tongue/mouth or finger in a patient with nosebleeds.
Mehl. Arteriovenous fistula.
be aware intraosseous AV fistulae can occur in Paget, as mentioned before.
