Venous hum of the Cruveilhier-Baumgarten syndrome: response to the Valsalva maneuver.

The response of the venous hum of the Cruveilhier-Baumgarten syndrome (CBS) to respiration, the cardiac cycle, and changes in posture is not predictable. The Valsalva maneuver may result in an increase in intensity of the hum rather than a decrease. The Cruveilhier-Baumgarten venous hum (CBH) is virtually diagnostic of portal vein hypertension. It may be mistaken for obscure cardiac murmurs. The Cruveilhier-Baumgarten venous hum, unlike the cervical venous hum (CVH), is never present in normal people.