This patient demonstrates the venous hum. This is a continuous murmur often first heard at the upper right sternal edge in a young child who is sitting upright. Loudest in the right supraclavicular fossa, the murmur accentuates in diastole. It is of variable frequency and loudness. It may radiate down either sternal edge. In normal supine children, the murmur is rarely audible. High output states, such as fever, anemia or hyperthyroidism may allow detection of a venous hum in a supine patient. Regardless of patient's position or cause, the venous hum can be eliminated by externally compressing the right jugular vein. Rotating the head may also accomplish this, doing so may occasionally elicit or accentuate it.
Rt jugular vein compression
Observe the effect of compressing the right jugular vein with the patient sitting up. This decreases volume flow sufficiently to decrease or eliminate the hum.
No compression
[Sounds]
Compression
[Sounds]
Etiology
The venous hum is due to turbulent flow in the region of the major cervical and thoracic veins as they form the superior vena cava. The murmur becomes louder in diastole, when the tricuspid valve opens and flow accelerates into the right ventricle. High cardiac output states, such as with fever and anemia, augment the venous hum.