May 30, 2018, 2:37:51 PM CDT Aug 8, 2019, 4:15:44 PM CDT

What parents should know about heart murmurs

A pediatric cardiologist explains common causes of heart murmurs in children and when treatment is necessary

Doctor listening to baby girl's heart while she is held by mom Doctor listening to baby girl's heart while she is held by mom

When it comes to your child's heart, anything "irregular" can seem scary. Heart murmurs can certainly fall into that category. But most of the time, heart murmurs in children are not dangerous or cause for concern, according to Thomas Zellers, M.D., a pediatric interventional cardiologist at Children's Health℠ and Professor at UT Southwestern.

"Most murmurs in otherwise healthy children are innocent or benign and are not caused by a heart abnormality," says Dr. Zellers. Learn more about types of heart murmurs in children.

What is a heart murmur?

A heart murmur is an extra sound made by the heart during a normal heartbeat. It can be heard listening to your heart using a stethoscope, and sounds like a rushing noise, like the sound of water coming through a hose.

Murmurs are diagnosed as either being innocent or abnormal, with the vast majority being innocent or benign. A child with a heart murmur can have a perfectly healthy heart.

Types of heart murmurs in children

There are five kinds of innocent murmurs that are often noticed in infants and do not require any treatment:

  1. Still's murmur
  2. Pulmonary flow murmur
  3. Venous hum
  4. Carotid bruit
  5. Peripheral pulmonary stenosis murmur

What causes a heart murmur?

Heart murmurs are caused by turbulent blood flow moving through the heart. In a normal heartbeat, valves open and close in the heart while blood moves from higher pressure areas to areas of lower pressure. In the case of murmurs, the rush of blood flowing makes an extra sound heard using a stethoscope. The bigger the change in pressure, the louder the murmur. For innocent heart murmurs, there is no underlying, structural cause of a murmur.

What are symptoms of a heart murmur?

In the case of innocent murmurs, your child will likely exhibit no symptoms since there are no associated structural abnormalities. The murmur itself may sound stronger if your child is sick, especially with fever, is going through a growth spurt or is vigorously exercising, but it is still harmless.

"Innocent heart murmurs do not cause symptoms because they do not represent any heart disease. These children have normal hearts and require no restrictions," says Dr. Zellers.

In the case of abnormal murmurs, the murmur is a symptom of a larger problem, such as a structural defect of the heart. The sound made by these murmurs is different than that made by an innocent murmur and can often be differentiated by your child's pediatrician using a stethoscope. Your pediatrician may send your child to a heart specialist if further testing is needed to evaluate the murmur.

How serious is a heart murmur in a child?

Innocent heart murmurs are not serious at all. Innocent murmurs should be noted, as the sound may be louder at certain times during a child's life, and it is important to inform medical personnel that the murmur has already been identified and is benign. Children with innocent murmurs do not have any restrictions on their activity, including participating in sports.

In the uncommon situation of a murmur caused by a structural heart defect (8 per 1000 live births), more testing may be required, and the cardiologist will work with you developing a care plan.

Can you treat a heart murmur?

Innocent heart murmurs do not require treatment. For murmurs caused by a structural heart problem, treatment is associated with improving the underlying condition causing the murmur.

Can a child grow out of a heart murmur?

Heart murmurs are most frequently heard in infants but can also be heard in toddlers and school age children. Murmurs may remain audible in thin children but may become less audible or even resolve as kids grow and build more musculature around the chest. Murmurs may be more audible at certain periods in a child's life, such as when he or she is ill or going through a growth spurt.

Learn more

The nationally renowned team of pediatric cardiologists and subspecialists at Children's Health treat the whole spectrum of pediatric heart problems, with a commitment to excellence. Learn more about our programs and treatments.

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cardiology, congenital disorders, heart, heart disease, heart health

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