Mehl. cardiac stress testing + atherosc. for MI table + statins Flashcards
Most 2CK Qs that ask about stress tests are in the context of evaluating patients for perioperative MI risk.
It is rare the Q will force you to choose between different types of stress tests. 4/5 Qs will just list one stress test, where it is simply assessing, “Do you know a stress test should be done, period, in this scenario.”
Stress tests are also done for peripheral arterial disease prior to recommending an exercise/walking program (as mentioned above).
Arterial disease in legs: ABI -> stress test –> prescription for an exercise program.
Most common stress test?
Exercise ECG
The answer on USMLE for patients who have stable angina, where you’re looking for ST depressions (i.e., evidence of ischemia) with exertion.
Exercise ECG
!!!!Requires a patient has a normal baseline ECG in order to perform. what test?
Exercise ECG
Exercise ECG. In other words, the Q will give you a big 15-line paragraph + mention in the last line that the patient’s baseline ECG shows, e.g., a LBBB from a year ago that’s unchanged.
This means ECG stress test is wrong in this situation, since you need to have a normal ECG todo it. The 1/5 Qs that force you to choose between stress tests want you to know this detail, basically, where you just choose the non-ECG stress test instead.
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Used to look for heart failure (i.e., decr. EF) with exertion, not overt ischemia. Test?
Exercise echo
In other words, the answer on USMLE for patients who don’t get chest pain with exertion (i.e., don’t have stable angina), but who get shortness of breath with exertion. TEST?
Exercise echo
SOB - this reflects, at a minimum, left heart decompensation with possible decr. EF
Also the answer for patients who have abnormal baseline ECG. TEST?
Exercise echo
Pharmacologic. Refers to numerous answer choices on USMLE – i.e., dobutamine-echo, dipyridamole- thallium.
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The answer on USMLE for patients who cannot exercise, such as in the setting of angina when merely walking up a single flight of steps, or in patients imminently undergoing major surgery (e.g., AAA repair), where perioperative MI risk needs to be assessed.
Pharmacologic test
Pharmacologic.
The USMLE will typically not force you to choose between stress tests. As I mentioned at the top of this table, they will usually just have the pharmacologic stress test as the only one listed.
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Pharmacologic. Dobutamine - group, moa?
b1-agonist that stimulates the heart (i.e., oxygen demand). Echo can then be done to look for decr. EF (i.e., heart failure).
Pharmacologic. Dipyridamole - group, moa?
Dipyridamole is a phosphodiesterase inhibitor that dilates arterioles.
HR goes up to compensate, thereby incr. myocardial oxygen demand. Thallium is then used to look at perfusion of the myocardium.
Cardiac scintigraphy. Cardiac scintigraphy” is a broad term that refers to any evaluation of the heart in which some form of radiotracer is used (i.e., thallium, technetium, sestamibi).
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Cardiac scintigraphy. This is the same as pharmacologic stress test for all intents and purposes on USMLE, even though technically it need not require myocardium is stimulated and can just be used to look at blood flow to the heart in the resting state.
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Cardiac scintigraphy.
The point is: This is an answer on 2CK sometimes as just another way of them writing “pharmacologic stress test.” Choose it if the patient cannot exercise.
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Myocardial perfusion scan.
“Myocardial perfusion scan” is one type of cardiac scintigraphy that evaluates blood flow to myocardium. It is non-invasive, whereas coronary angiography is invasive and evaluates coronary blood flow via the use of a catheter.
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Myocardial perfusion scan.
This is interchangeable with cardiac scintigraphy and pharmacologic stress test on USMLE for all intents and purposes
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Atherosclerosis for IM. - Most acceleratory risk factors are ?
diabetes mellitus (I and II), followed by smoking, followed by HTN, in that order.
Atherosclerosis for IM. HTN is most common risk factor, but DM and smoking are worse.
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Atherosclerosis for IM. HTN is most acceleratory specifically for….?
carotid stenosis (systolic impulse pounds carotids -> endothelial damage).
Atherosclerosis for IM.
Stroke, TIA, or retinal artery occlusion in patient with high BP is due to?
due to carotid plaque launching off to the brain/eye.
Atherosclerosis for IM. If patient has normal BP + Stroke, TIA, or retinal artery occlusion -> think about what?
think AF instead, with left atrial mural thrombus launching off.
Atherosclerosis for IM.
Patient over 50 with Hx of cardiovascular risk factors who now has accelerated HTN, think about what reason?
think renal artery stenosis (narrowing due to atherosclerosis).
Atherosclerosis for IM.
Plaques can calcify. The more calcium there is in a plaque, the more mature it is often considered to be. Calcium scoring is routinely done in patients who have coronary artery disease in the assessment of plaque progression.
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Atherosclerosis for IM. Statins have 2 HY MOAs on USMLE:?
1) inhibit HMG-CoA reductase; 2) upregulate LDL receptors on hepatocytes.
Atherosclerosis for IM. Ezetimibe moa?
blocks cholesterol absorption in the small bowel.
Atherosclerosis for IM. Bile acid sequestrants (e.g., cholestyramine). Mechanism?
result in the liver pulling more cholesterol out of the blood.
Atherosclerosis for IM. Fibrates, moa?
upregulate PPAR-a and lipoprotein lipase; best drugs to decrease triglycerides.
Statins. Can cause what 2 adverse?
Can cause myopathy and toxic hepatitis.
Statins. myopathy vs toxic hepatitis.?
An offline NBME has myopathy as correct over toxic hepatitis.
Statins. Indications for statins on 2CK vary depending on the source (i.e., whether to use the 70 vs 100 mg/dL cutoff in certain scenarios), but for IM, give if: Age 20-39 if LDL?
> 190 mg/dL.
Statins. Indications for statins, Age 40-75?
LDL > 100 mg/dL.
Statins. Indications for statins, Age 20-75 + DM?
if LDL >100 mg/dL.
Statins. Age 20-75 + DM.
Some sources use 70, rather than 100, for the latter two cutoffs. What I can say is that I’ve seen 2CK NBME Qs where they use 100 as the cutoff (i.e., they give an LDL of 95 and statin is wrong, implying LDL is satisfactory).
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Statins. Some sources incorporate a CVD risk % of >7.5%, which is more of a moot / pedantic talking point. I’ve seen one 2CK NBME Q where a CVD risk % shows up in the stem, but it doesn’t rely on you knowing that point to get it right.
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Fibrates. Give if triglycerides >?
> 300 mg/dL.
Fibrates. adverse? 3
Can cause myopathy and hepatotoxicity, as well as cholesterol gall stones.
Fibrates. If the USMLE asks you why statins + fibrates combined have incr. chance of myopathy, the answer is???
P-450 interaction.
Ezetimibe.
Blocks cholesterol absorption in the small bowel, thereby decr. LDL.
USMLE just wants you to know MOA.
Doesn’t decrease mortality.
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Cholestyramine. Causes reduced enterohepatic circulation of bile acids at terminal ileum -> liver must now convert more cholesterol into bile acids in order to replenish them -> liver pulls cholesterol out of the blood to accomplish this.
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