CSC CSC 5 — Questions and Answers
Question 1: A 68-year-old with chronic kidney disease and new-onset atrial fibrillation requires anticoagulation. His CrCl is 28 mL/min. Which DOAC requires the most significant dose adjustment?
- Rivaroxaban
- Apixaban
- Dabigatran (Correct answer)
- Edoxaban
Correct answer: Dabigatran
Dabigatran is 80% renally cleared and is contraindicated when CrCl <30 mL/min (FDA) or <15 mL/min (European guidelines), making renal function the critical determinant of dosing.
Question 2: Which hemodynamic change characteristically occurs with inspiration during cardiac tamponade?
- Decrease in right heart pressures and increase in left heart filling
- Equalization of right and left heart diastolic pressures
- Paradoxical pulse with ≥10 mmHg drop in systolic BP during inspiration (Correct answer)
- Kussmaul's sign with a rise in JVP during inspiration
Correct answer: Paradoxical pulse with ≥10 mmHg drop in systolic BP during inspiration
Pulsus paradoxus (≥10 mmHg inspiratory fall in SBP) occurs in tamponade because inspiratory RV filling competes with LV in the constrained pericardial space, reducing LV output.
Question 3: A patient is started on amiodarone for recurrent VT. Which side effect requires monitoring with annual pulmonary function tests and chest radiography?
- Hepatotoxicity
- Thyroid dysfunction
- Pulmonary toxicity (Correct answer)
- Corneal microdeposits
Correct answer: Pulmonary toxicity
Amiodarone pulmonary toxicity (0.1–0.5%/year) is potentially fatal and requires surveillance with annual PFTs and CXR, including DLCO measurement.
Question 4: Which finding on cardiac MRI is most diagnostic of cardiac sarcoidosis?
- Sub-endocardial late gadolinium enhancement in a coronary distribution
- Mid-wall or epicardial late gadolinium enhancement in a non-ischemic pattern (Correct answer)
- Diffuse T1 signal prolongation throughout the myocardium
- Right ventricular fibrofatty replacement
Correct answer: Mid-wall or epicardial late gadolinium enhancement in a non-ischemic pattern
Cardiac sarcoidosis shows non-ischemic late gadolinium enhancement (mid-wall/epicardial, typically basal-septal or lateral), distinguishing it from ischemic cardiomyopathy's subendocardial pattern.
Question 5: A patient with HFrEF (EF 30%) develops worsening kidney function after starting an ACE inhibitor. Creatinine increases 25%. What is the appropriate management?
- Immediately stop the ACE inhibitor
- Continue ACE inhibitor if creatinine rise is ≤30% and potassium remains <5.5 mEq/L (Correct answer)
- Switch to a loop diuretic
- Add an ARB to compensate
Correct answer: Continue ACE inhibitor if creatinine rise is ≤30% and potassium remains <5.5 mEq/L
A creatinine rise up to 30% above baseline after RAAS inhibitor initiation is acceptable and expected due to reduced efferent arteriolar tone; discontinuation is only needed for larger rises or hyperkalemia.
Question 6: A 40-year-old woman with systemic lupus erythematosus develops new mitral regurgitation and vegetations on the mitral valve without fever or positive blood cultures. Which diagnosis best explains these findings?
- Infective endocarditis
- Libman-Sacks endocarditis (Correct answer)
- Rheumatic heart disease
- Marantic endocarditis
Correct answer: Libman-Sacks endocarditis
Libman-Sacks endocarditis is a non-infective verrucous endocarditis associated with SLE and antiphospholipid syndrome, typically involving both surfaces of valve leaflets.
Question 7: Which maneuver would cause the murmur of hypertrophic obstructive cardiomyopathy (HOCM) to increase in intensity?
- Passive leg elevation
- Squatting from standing position
- Standing from squatting position (Correct answer)
- Hand grip exercise
Correct answer: Standing from squatting position
Standing from squatting reduces venous return and LV volume, increasing LVOT obstruction and intensifying the HOCM murmur; squatting does the opposite.
CSC CSC 5
A 68-year-old with chronic kidney disease and new-onset atrial fibrillation requires anticoagulation.
His CrCl is 28 mL/min.
Which DOAC requires the most significant dose adjustment?