Mehl. cardio vessels: coarct., subclavian, vertebral etc Flashcards
(30 cards)
Mehl. Coarctation of the aorta. definition?
Refers to narrowing of the aortic arch (this is referred to as coarctation; do not use the word stenosis to describe this).
Mehl. Coarctation of the aorta. Classically seen in what syndrome?
Classically seen in Turner syndrome, but absolutely not mandatory.
Shows up idiopathically in plenty of NBME Qs. I point this out because students often think the patient must have Turner syndrome.
Mehl. Coarctation of the aorta. CP?
Presents as upper extremities that have higher BP, brisk pulses, and are warmer; the lower extremities have lower BP, weak pulses, and are cooler.
Mehl. Coarctation of the aorta.
Sometimes the Q can just say, “the radial pulses are brisk -> The implication is, “Well if they’re saying specifically that the radial pulses are brisk, that must mean the pulses in the legs aren’t.”
Murmur sound not important for USMLE. Can sometimes be described as a systolic murmur heart in the infrascapular region.
Mehl. Coarctation of the aorta.
ECG?
Can cause LVH with left-axis deviation ECG.
Mehl. Coarctation of the aorta.
USMLE doesn’t give a fuck about pre- vs post-ductal. Pre-ductal in theory will be a very sick neonate. Post-ductal will be an adult (most cases)
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Mehl. Subclavian steal syndrome. mechanism?
The vertebral artery (goes to brain) is the first branch of the subclavian artery (goes to arm).
If there is a narrowing/stenosis of the proximal subclavian prior to the branch point of the vertebral artery, this can lead to lower pressure in the vertebral artery.
This can cause a backflow of blood in the vertebral artery, producing miscellaneous neuro findings such as dizziness.
Mehl. Subclavian steal syndrome. BP?
Blood pressure is different between the two arms.
Mehl. Subclavian steal syndrome. USMLE will ask the Q one of two ways: 1?
1) they’ll give you dizziness in someone who has BP different between the arms and then ask for merely “subclavian steal syndrome,” or “backflow in a vertebral artery” as the answer.
Mehl. Subclavian steal syndrome.
USMLE will ask the Q one of two ways: 2?
2) they’ll give you BP in one of the arms + give you dizziness, then the answer will be, “Check blood pressure in other arm.”
Mehl. Subclavian steal syndrome. next step in Dx
CT or MR angiography
Mehl. Subclavian steal syndrome.
I should point out that probably 3/4 questions on USMLE where blood pressure is different between the arms, this refers to aortic dissection.
But 1/4 is subclavian steal syndrome. As per my observation.
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Mehl. Vertebral artery stenosis. Cause?
Caused by atherosclerosis.
Mehl. Vertebral artery stenosis. CP?
Presents same as subclavian steal syndrome with otherwise unexplained dizziness, but blood pressure is not different between the arms because the subclavian is not affected.
Mehl. Vertebral artery stenosis VS subclavian??
subclavian - different BP in arms
vertebral artery - blood pressure is not different between the arms because the subclavian is not affected.
Mehl. Vertebral artery stenosis. Dx?
CT or MR angiography can diagno
Mehl. Vertebral artery stenosis.
“Vertebrobasilar insufficiency” is a broader term that refers to patients who have either subclavian steal syndrome or vertebral artery stenosis
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NBME 10. 167.
A 66-year-old woman comes to the office because of a 6-month history of severe dizziness and a spinning sensation that occurs when she looks up or turns her head quickly. She says she fell 1 week ago during an episode. At that time, she had a brief episode of double vision. She also has a 2-year history of moderate neck pain, which she attributes to “muscle spasms”; since her fall, her pain has become more severe. She has hypertension and type 2 diabetes mellitus. Her medications are lisinopril and metformin. Her mother had a cerebral infarction at the age of 70 years. The patient has smoked one-half pack of cigarettes daily for 40 years. Her pulse is 84/min, and blood pressure is 150/85 mm Hg. Examination shows no nystagmus. Visual field testing shows no abnormalities. There are no cervical bruits. On palpation of the posterior muscles of the neck, there is mild tenderness that increases when the neck is rotated gently. Cardiopulmonary examination shows no abnormalities. Muscle strength is 5/5 in all extremities. Which of the following is the most likely explanation for this patient’s symptoms
Vertebral artery stenosis
This patient likely has a stenosis of the left vertebral artery leading to vertebrobasilar insufficiency
NBME 10. 167. Vertebral artery stenosis.
Vertebrobasilar insufficiency refers to??? caused???
transient ischemic attacks (TIAs) of the vertebrobasilar territory (also known as the posterior circulation) and can be caused by stenosis secondary to atherosclerotic buildup, thromboembolism, or vertebral artery dissection.
NBME 10. 167. Vertebral artery stenosis. look for atherosclerosis risk factors!
This patient possesses several risk factors for atherosclerosis, including smoking, hypertension, and diabetes mellitus.
NBME 10. 167. Vertebral artery stenosis.
Neck rotation commonly alters blood flow in the vertebral artery and may lead to transient ischemia, especially in patients with existing vertebral artery stenosis.
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NBME 10. 167. Vertebral artery stenosis. what supplies vertebral artery?
brainstem, cerebellum, and occipital lobes.
Patients typically present with transient vestibulocerebellar signs (ataxia, dysmetria, dizziness, imbalance, vertigo, vomiting, nystagmus), ipsilateral cranial nerve dysfunction (dysphagia, dysarthria, vertical or horizontal gaze palsies), contralateral hemiparesis (caused by corticospinal tract damage), contralateral impairment in pain and temperature sensation (caused by spinothalamic tract damage), and/or potential contralateral homonymous hemianopsia with macular sparing (as a result of occipital lobe involvement).
NBME 10. 167. Vertebral artery stenosis. secondary prevention?
In patients with vertebrobasilar insufficiency, secondary prevention of future TIAs or strokes should include smoking cessation, blood pressure reduction, blood glucose control, a healthy diet, regular exercise, and use of a statin and aspirin.
Mehl. Vertebral artery dissection.
2CK forms assess vertebral artery dissection, where they want you to know a false lumen created by dissection in a vertebral artery can lead to stasis and clot formation, which in turn can embolize to the brain and cause stroke.
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