skip to main content

Innocent murmur — USMLE Step 3 MCQ

Instant feedback + full explanation. One question, done properly.

EasyAmbulatory Medicine / Primary CareInnocent murmurUSMLE Step 3

A 5-year-old boy has a soft grade 2/6 systolic murmur at the left lower sternal border during a well-child visit. It is louder when supine and softer when standing. He has normal growth, no cyanosis, normal pulses, and no exercise intolerance. Which of the following is the most likely explanation for this patient's findings?

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

Reveal the answer and explanation

Correct answer: B — Innocent vibratory flow murmur

A soft systolic murmur that decreases with standing in an asymptomatic child with normal examination findings is typical of an innocent Still murmur.

Reference: AAP pediatric heart murmur evaluation guidance