Internal Medicine Exam Acute Coronary Syndromes 4 โ Questions and Answers
Question 1: A 55-year-old man with prior PCI (bare-metal stent placed 1 month ago) requires urgent non-cardiac surgery. What is the recommended approach to his dual antiplatelet therapy (DAPT)?
- Stop both aspirin and clopidogrel 5 days before surgery
- Continue aspirin, stop P2Y12 inhibitor 5-7 days before surgery
- Continue both antiplatelet agents perioperatively (Correct answer)
- Switch to LMWH bridging therapy
Correct answer: Continue both antiplatelet agents perioperatively
For bare-metal stents within 4 weeks of placement, elective surgery should be deferred; if surgery is truly urgent, continuing DAPT perioperatively is preferred to prevent stent thrombosis.
Question 2: Which biomarker has the fastest rise-and-fall kinetics and was historically used for early diagnosis of re-infarction after STEMI?
- Troponin I
- Troponin T
- CK-MB (creatine kinase-MB) (Correct answer)
- Myoglobin
Correct answer: CK-MB (creatine kinase-MB)
CK-MB rises and falls more rapidly than troponin (peaks at 24h, normalizes by 48-72h), making it useful for detecting re-infarction when troponin remains elevated from the initial event.
Question 3: Wellens' syndrome (Type A and B T-wave patterns in V2-V3) in a patient with resolved chest pain indicates which critical finding?
- Prior completed MI with scar formation
- Critical proximal LAD stenosis with intermittent reperfusion (Correct answer)
- Hyperkalemia causing diffuse T-wave changes
- Benign early repolarization
Correct answer: Critical proximal LAD stenosis with intermittent reperfusion
Wellens' syndrome represents reperfusion T-wave changes from a critical proximal LAD lesion; stress testing is contraindicated as it can precipitate massive anterior STEMI.
Question 4: A patient with ACS is found to have a platelet count of 48,000/ฮผL after receiving heparin for 7 days. The most likely diagnosis is:
- Immune thrombocytopenic purpura (ITP)
- Heparin-induced thrombocytopenia (HIT) (Correct answer)
- Thrombotic thrombocytopenic purpura (TTP)
- Dilutional thrombocytopenia
Correct answer: Heparin-induced thrombocytopenia (HIT)
HIT is characterized by a >50% platelet drop 5-10 days after heparin initiation, associated with a prothrombotic state rather than bleeding, and requires immediate heparin cessation and alternative anticoagulation.
Question 5: Which finding on echocardiogram performed after STEMI is associated with the highest risk of systemic embolization?
- Mild LV diastolic dysfunction
- Apical left ventricular thrombus (Correct answer)
- Moderate mitral regurgitation
- Trivial pericardial effusion
Correct answer: Apical left ventricular thrombus
LV thrombus, most common after large anterior STEMI with apical akinesis, carries significant risk of systemic embolization and stroke, requiring anticoagulation therapy.
Question 6: Cocaine-induced ACS is best managed with which of the following agents?
- IV beta-blockers alone
- Benzodiazepines plus nitroglycerin; avoid beta-blockers (Correct answer)
- Immediate high-dose thrombolytics
- Propranolol to counteract catecholamine surge
Correct answer: Benzodiazepines plus nitroglycerin; avoid beta-blockers
Cocaine-induced ACS is treated with benzodiazepines (to reduce sympathetic drive) and nitrates; non-selective beta-blockers are contraindicated as they can cause unopposed alpha-adrenergic coronary vasospasm.
Question 7: A 64-year-old woman is diagnosed with Takotsubo (stress) cardiomyopathy after an emotional stressor. Which angiographic finding distinguishes this from anterior STEMI?
- ST elevation in leads V1-V4
- Apical ballooning with normal or non-obstructive coronary arteries (Correct answer)
- Troponin elevation >10x upper limit of normal
- Complete AV block
Correct answer: Apical ballooning with normal or non-obstructive coronary arteries
Takotsubo cardiomyopathy shows apical LV ballooning with hypercontractile base on ventriculography, with absent or non-obstructive coronary artery disease on angiography, distinguishing it from anterior STEMI.
Internal Medicine Exam Acute Coronary Syndromes 4
A 55-year-old man with prior PCI (bare-metal stent placed 1 month ago) requires urgent non-cardiac surgery.
What is the recommended approach to his dual antiplatelet therapy (DAPT)?