Ebstein anomaly is a rare heart defect that affects the
tricuspid valve (one of the heart's four valves). It happens because of a problem
with how the valve forms before a baby's birth.
What Happens in Ebstein Anomaly?
Anomaly means "something different." In Ebstein anomaly, the "something
different" is the position of the tricuspid valve and the way its parts move.
The tricuspid valve sits between the upper right chamber (right atrium) and the
lower right chamber (right ventricle) of the heart.
Normally, when the heart muscle relaxes, this valve is open, allowing blood to flow
into the right ventricle. When the right ventricle squeezes to pump blood out of the
heart, the tricuspid valve's three "leaflets" close to prevent backward
leakage of blood from the right ventricle to the right atrium.
In Ebstein anomaly, the valve is sunken into the right ventricle, and one or two
of its leaflets are stuck to the heart wall. The third leaflet is usually floppy.
This prevents the valve from working well. Often, the valve can't close completely,
so blood leaks back through the tricuspid valve into the right atrium. When a lot
of blood leaks backwards, this enlarges the right atrium and makes the right ventricle
Less commonly, the tricuspid valve in Ebstein anomaly is tight, preventing normal
forward flow from the right atrium to the right ventricle. In some cases, the right
ventricle is too small to pump enough blood to meet the body's needs. All of these
problems may make it harder for the heart to pump blood efficiently.
What Are the Signs & Symptoms of Ebstein Anomaly?
Ebstein anomaly can cause problems that range from very mild to very serious. Kids
with a milder form of the anomaly may not have any symptoms until they're older.
Two signs that an infant or child may have Ebstein anomaly are trouble breathing
and a bluish coloring of the skin and nails (cyanosis).
Ebstein anomaly also can make a child:
fail to grow as expected
feel short of breath
cough a lot
feel a rapid heartbeat (palpitations)
struggle to keep up with other kids in physical activities
In severe cases, a child also might have swelling (edema) in the legs or fluid
in the belly (ascites). Doctors often hear extra heart sounds, including a murmur,
when listening to a child's heartbeat.
A baby born with Ebstein anomaly often has other heart problems, such as an atrial septal defect (an abnormal
hole between the upper chambers of the heart) or a patent
foramen ovale (PFO, a normal opening between the upper chambers of the heart that
usually closes shortly after birth). When either of these holes are open, oxygen-poor
blood from the right side of the heart can leak into the left side of the heart and
out to the body. This leads to a lower oxygen level in the bloodstream and the bluish
color of the lips and nailbeds.
In some children with Ebstein anomaly, the pulmonary valve (the other valve on
the right side of the heart) may also be tight (called pulmonary
stenosis) or even sealed off (pulmonary atresia). These pulmonary valve problems
also contribute to cyanosis.
Ebstein anomaly often affects the heart's electrical system. Some kids will have
an extra electrical pathway called Wolff-Parkinson-White syndrome (WPW), which can
cause a very fast heartbeat (tachycardia) or an unsteady beat.
What Causes Ebstein Anomaly?
Doctors don't know exactly why a baby's heart develops Ebstein anomaly during pregnancy.
But it isn't caused by anything a mother does or doesn't do during her pregnancy.
Who Gets Ebstein Anomaly?
Most cases of Ebstein anomaly are an accidental error of growth during pregnancy.
Some genetic links have been found, but most cases don't have a known genetic cause.
How Is Ebstein Anomaly Diagnosed?
Ebstein anomaly might be seen on ultrasound
scans before birth. It may be recognized at birth because the baby's skin looks blue
or the baby's heart makes unusual sounds.
The best test to confirm Ebstein anomaly is an echocardiogram
(ultrasound of the heart).
electrocardiogram (also called
ECG or EKG), a recording of the heart's electrical activity. It may show abnormal
heartbeats or signs that the heart's right chambers are enlarged.
exercise test (for older kids who can follow instructions)
How Is Ebstein Anomaly Treated?
If the defect was found before birth, the delivery team will be ready to provide
intensive care immediately in case the newborn is not doing well. But most newborns with the anomaly don't need immediate treatment. Doctors will monitor
them closely to watch for changes and provide quick treatment if needed.
Some children with Ebstein anomaly don't need treatment. When treatment is needed, the most common types used are:
Extra oxygen can help increase the amount of oxygen in the blood, and help the
heart meet the body's needs.
If a baby's life is in danger, urgent surgery may be done within a few days of
birth. A baby with less serious effects may have surgery months to years later.
Medicines can help keep the heart from beating too fast and treat heart failure
(when the heart can't meet the body's demands) if it develops.
Doctors may recommend an electrophysiology study (EP study) when there are serious
abnormal heart rhythms. During this study,
(freezing or burning) can get rid of electrical pathway fibers that make
the heart beat too fast.
Babies with Ebstein anomaly need care from a pediatric cardiologist (a doctor who
specializes in treating heart problems) because the heart's pumping ability may fall
short as the child grows. The doctor will recommend treatment that is tailored to
a child's needs.
Many children whose Ebstein anomaly was corrected by surgery can be as active as