In a child, a rumbling murmur heard in the neck that disappears when the child is supine and the neck rotated indicates which benign murmur?

• A. Aortic stenosis
• B. Carotid bruit
• C. Patent ductus arteriosus
• D. Venous hum

Answer: (D)

This is a venous hum, a harmless pediatric murmur caused by turbulence in the jugular venous system. It tends to be a soft, continuous, low-pitched rumble heard best in the neck area, often above the clavicle near the jugular veins. A hallmark feature is its dependence on posture: it is loud when the child is upright but fades or disappears when the child lies down and when the neck is rotated. Neck rotation can compress or kinks the jugular veins, reducing the flow that creates the sound, so the murmur vanishes.

This pattern helps distinguish it from other murmurs. For example, aortic stenosis is a systolic murmur heard at the right upper sternal border and wouldn’t simply disappear with changing position. A patent ductus arteriosus produces a continuous murmur best heard under the left clavicle, not limited to the neck and not typically abolished by neck rotation. A carotid bruit is heard over the carotid arteries and isn’t the classic benign, posture-dependent neck murmur seen in children.