CSC CSC 4 — Questions and Answers
Question 1: A patient with dilated cardiomyopathy and LBBB (QRS 158 ms) and EF of 25% is on optimal medical therapy. Which CRT criterion is not met if the patient is NYHA Class I?
- QRS duration requirement
- EF threshold
- LBBB morphology requirement
- Symptom threshold for Class I recommendation (Correct answer)
Correct answer: Symptom threshold for Class I recommendation
Current guidelines recommend CRT for NYHA Class II–IV patients; Class I is generally not an indication, as mortality benefit requires a minimum symptom burden.
Question 2: Which pharmacologic stress agent is contraindicated in patients with severe reactive airway disease undergoing pharmacologic stress testing?
- Regadenoson
- Dobutamine
- Adenosine (Correct answer)
- Dipyridamole
Correct answer: Adenosine
Adenosine causes severe bronchospasm via A2B receptor activation and is contraindicated in reactive airway disease; regadenoson (selective A2A agonist) is relatively safer but still used cautiously.
Question 3: A patient with known aortic stenosis has an aortic valve area of 0.7 cm² but a mean gradient of only 22 mmHg due to low cardiac output. How is this best categorized?
- Moderate aortic stenosis
- Severe high-gradient aortic stenosis
- Low-flow, low-gradient severe aortic stenosis (Correct answer)
- Pseudosevere aortic stenosis
Correct answer: Low-flow, low-gradient severe aortic stenosis
Low-flow, low-gradient severe AS occurs when reduced stroke volume limits gradient despite truly severe valve obstruction; dobutamine stress echo helps distinguish true from pseudosevere AS.
Question 4: A 55-year-old athlete presents with syncope during exercise. ECG shows epsilon waves and T-wave inversions in V1–V3. Which diagnosis is most likely?
- Brugada syndrome
- Arrhythmogenic right ventricular cardiomyopathy (ARVC) (Correct answer)
- Long QT syndrome
- Hypertrophic cardiomyopathy
Correct answer: Arrhythmogenic right ventricular cardiomyopathy (ARVC)
ARVC classically presents with epsilon waves, T-wave inversions in right precordial leads, and exercise-induced ventricular arrhythmias due to fibrofatty RV replacement.
Question 5: Which anticoagulation strategy is recommended for a patient with AF and a CHA₂DS₂-VASc score of 2 who requires bridging therapy before elective surgery?
- Stop anticoagulation 48 hours before and restart immediately post-op
- Use LMWH bridging therapy routinely
- No bridging required for most AF patients on warfarin (Correct answer)
- Switch to aspirin perioperatively
Correct answer: No bridging required for most AF patients on warfarin
The BRIDGE trial demonstrated that forgoing bridging anticoagulation in AF patients was non-inferior to LMWH bridging, with lower bleeding risk and no increase in thromboembolism.
Question 6: A patient with inferior MI develops sudden hypotension, clear lung fields, and elevated JVP. Which complication is most likely?
- Left ventricular free wall rupture
- Acute mitral regurgitation from papillary muscle rupture
- Right ventricular infarction (Correct answer)
- Ventricular septal defect
Correct answer: Right ventricular infarction
RV infarction complicates inferior MI (RCA territory) and presents with hypotension, elevated JVP, and clear lungs because the failing RV cannot fill the LV adequately.
Question 7: Which echocardiographic parameter best estimates LV filling pressures non-invasively in a patient with HFpEF?
- LV ejection fraction
- Mitral annular E/e' ratio (Correct answer)
- LV end-diastolic volume
- Right ventricular systolic pressure alone
Correct answer: Mitral annular E/e' ratio
The E/e' ratio (transmitral E velocity divided by tissue Doppler e' velocity) correlates with PCWP and is the primary non-invasive estimator of LV filling pressures.
CSC CSC 4
A patient with dilated cardiomyopathy and LBBB (QRS 158 ms) and EF of 25% is on optimal medical therapy.
Which CRT criterion is not met if the patient is NYHA Class I?