Heart Failure USMLE Step 1 Practice Question
A 17-year-old competitive basketball player presents with exertional syncope and dyspnea on exertion. Vital signs show BP 118/76 mmHg, HR 92 bpm, RR 18, and SpO2 98% on room air. Examination reveals a harsh systolic murmur that increases with standing and Valsalva maneuver. Echocardiography demonstrates asymmetric septal hypertrophy with an outflow gradient of 65 mmHg. He denies palpitations. He takes no medications. Which arrhythmic complication most likely explains his sudden cardiac death risk?
Answer choices
- AAccessory pathway-mediated orthodromic SVT
- BMultifocal atrial tachycardia due to pulmonary disease
- CVentricular tachyarrhythmia arising in a hypertrophied myocardiumCorrect answer
- DAtrial flutter due to right atrial enlargement
- EComplete heart block due to AV nodal infarction
- FAtrioventricular reentrant tachycardia due to accessory pathway conduction
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations ā plus adaptive practice that targets your weak areas ā with a free MedBoardPRO account.