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Heart failure with reduced ejection fraction — USMLE Step 3 MCQ

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HardInternal Medicine (chronic management)Heart failure with reduced ejection fractionUSMLE Step 3

A patient with nonischemic cardiomyopathy remains NYHA class II despite full guideline-directed therapy. LVEF is 28%, sinus rhythm is present and ECG shows left bundle-branch block with QRS 168 ms. What is the best device strategy?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: C — Refer for cardiac resynchronization therapy with defibrillator assessment

Explanation lettering: C = shown as A · E = shown as B · A = shown as C · B = shown as D · D = shown as E

Reduced LVEF, symptoms, sinus rhythm, LBBB and QRS at least 150 ms support CRT, often with defibrillator assessment. B does not resynchronize. C is harmful in HFrEF. D and E do not address the indicated first device strategy.

Reference: ACC/AHA/HFSA, Heart Failure Guideline: https://www.acc.org/Guidelines