Parents are understandably concerned when the doctor says their child has a murmur or other atypical heart sound. Heart murmurs are fairly common in children, and, in most cases, they occur in children with normal, healthy hearts. Many children outgrow these “benign” murmurs with time. There’s another type of sound that doctors hear commonly when they listen to a child’s heart called a venous hum. What is a venous hum – and should you be concerned if your child has one?
What is a Venous Hum?
A venous hum is a sound doctors hear when they place the stethoscope on a child’s upper chest wall. Unlike a heart murmur, that’s heard only during certain phases of the heart cycle, a venous hum is a continuous sound heard throughout the cycle of the heartbeat.
A venous hum is caused by slight narrowing of the jugular veins that drain blood from the head and brain. The jugular veins run down both sides of the neck. As they pass underneath the collarbone, they pressure of the bone causes them to narrow slightly. This creates a turbulent sound – best heard when listening to the upper chest wall with a stethoscope. A venous hum has a humming or “swooshing” sound, and it may be confused with a heart murmur.
Venous hums can be distinguished from a heart murmur by pressing on the jugular veins when listening to the chest near the collarbone. This usually dampens or eliminates the “hum”. A venous hum may also disappear when a child assumes certain positions.
Is a Venous Hum in Children Significant?
Up to one in five children will have a venous hum at some point during their life, and, in the absence of other abnormalities, it isn’t a sign of heart disease. A venous hum in a child is usually nothing to be concerned about, and it may come and go over time.
Venous Hums in Adults
Even adults can have a venous hum. According to one survey of 200 people, almost half of all young adults have a venous hum on exam, and over 20% of middle-aged and older adults do too. Care must be taken to ensure that the hum disappears when pressure is applied to the jugular vein. If it doesn’t, the sound may not be a benign venous hum at all, but a sign of an AV malformation or carotid stenosis – a more serious condition where the carotid arteries become narrowed. Carotid artery stenosis can lead to a stroke. Venous hums are also more commonly heard in people with anemia or an overactive thyroid gland.
What is a Venous Hum: The Bottom Line?
Venous hums are common in children and adults. Adults with a venous hum should be carefully examined to make sure the sound truly is a venous hum and not a sign of other problems such as carotid artery narrowing. In children, a venous hum is usually nothing to worry about.
References:
Calif. Med. August; 105(2): 102-103. August 1966.
Child Heart Associates. “Venous Hum”.
