Hypoplastic Left Heart Syndrome (HLHS) in Children
Overview
Hypoplastic left heart syndrome (HLHS) is a group of defects of the heart and large
blood vessels. A child is born with this condition (congenital heart defect). It occurs
when part of the heart doesn't develop as it should during the first 8 weeks of
pregnancy.
In
HLHS, most of the left side of the heart is small, underdeveloped, or both. The
following structures are usually affected:
-
Mitral
valve.
This valve controls blood flow between the left atrium and left
ventricle.
-
Left
ventricle.
This is the lower left chamber of the heart. It pumps blood to the
body.
-
Aortic
valve.
This valve controls blood flow from the left ventricle into the aorta,
and then to the body. The aorta is the major blood vessel that delivers blood to the
body.
-
Aorta.
This is the large artery leading from the left ventricle to the body.
The
left ventricle is normally very strong, so it can pump blood to the body. When it
is
small and poorly developed, it can't pump any or enough blood out to the body. For
this
reason, a baby with HLHS will not survive without surgery to fix the defect.
Causes
A
child is born with this condition (congenital). Some congenital heart defects occur
more
often in certain families (genetic defects).
In many children, HLHS occurs by chance. There is no clear reason for its development.
Symptoms
Babies with hypoplastic left heart syndrome usually get symptoms shortly after
birth:
- Blue color of the skin, lips, and nails (cyanosis)
- Pale skin
- Sweaty, clammy, or cool skin
- Trouble breathing
- Fast heart rate
- Cold feet
- Poor pulses in the feet
- Poor feeding
The
symptoms of HLHS may look like other health conditions and heart problems. Your child
needs to see a healthcare provider for a diagnosis.
Diagnosis
In
many cases, hypoplastic left heart syndrome can be diagnosed with an ultrasound while
the baby is still in the womb (uterus). After birth, you or your healthcare provider may
notice that your baby seems limp or listless, has trouble breathing, or has a blue
color
to their skin, lips, or nails. Your child will need a pediatric cardiologist to make
the diagnosis. This is a doctor with special training in treating heart problems
in
children.
The
cardiologist will examine your baby, listen to their heart and lungs, and make other
observations. Testing for congenital heart disease varies. Your child may have these
tests:
-
Echocardiogram (echo). An echo uses sound waves to make moving pictures of
the heart and heart valves. Children with HLHS are almost always diagnosed by
echocardiography.
-
Chest X-ray. A chest X-ray
may show problems that appear with HLHS.
-
Electrocardiogram (ECG). An ECG records the electrical activity of the
heart. It shows abnormal rhythms (arrhythmias) and finds heart muscle damage.
Treatment
Your
baby will most likely be cared for in the neonatal intensive care unit (NICU). At
first,
they may get oxygen or be placed on a ventilator. This is to help with breathing.
Your
child may get IV medicine. The medicine helps the heart and lungs work.
In
most cases, surgery is used to treat hypoplastic left heart syndrome. Your baby’s
cardiologist and cardiac surgeon will explain the risks and benefits. A heart transplant
is another option. But it can be very difficult to find a donor heart for a baby.
Also,
the child will need to take medicines for the rest of their life to prevent
rejection.
Surgery typically involves at least a series of several surgeries. In this very complex
treatment, the surgeon redirects blood flow to the lungs and the body through several
connections. The surgery is done in stages. The first surgery is done shortly after
birth. The second stage is done between ages 4 to 6 months, and the third stage is
done
between ages 18 months and 3 years. Another option for treatment of HLHS is a
combination of surgery and cardiac catheterization. This is called a hybrid procedure.
It accomplishes the goal of the first surgery without the need for placing your child
on
a heart-lung machine. This procedure is typically reserved for children who are at
high
risk, such as prematurity, low birth weight, and organ dysfunction.
After
the surgery, your baby will return to the pediatric intensive care unit (PICU) to
be
closely watched. After the first surgery, you can expect your child to be in the
hospital for several weeks. When your child is well enough to go home, they will most
likely require oral medicines such as diuretics. In addition, your baby may require
assistance with feeding using a feeding tube. The healthcare provider may recommend
pain
medicine such as acetaminophen or ibuprofen to keep your child comfortable. Your
child's healthcare provider will discuss pain control before your baby goes home.
Typically, after the first surgery, your baby will need frequent monitoring even when
home. This may involve frequent phone calls with the medical team, daily checks of
your
baby's oxygen levels, and daily weights. Many centers have specialized programs that
help families and train them in how to care for the baby at home. If any special
treatments are to be given at home, the nursing staff will make sure that you or a
home
health agency is able to provide them.
You may get other instructions from your child's healthcare providers and the hospital
staff.
Living with
A
baby with hypoplastic left heart syndrome needs surgery to survive.
The
first stage of the surgery has the highest risk for complications and death. Some
special treatment centers that do many of these procedures have higher survival rates
than centers where fewer procedures are done. Survival rates are higher with the second
and third stages of surgery.
Babies and children who have the staged surgeries will need special care and treatment
to support growth and development. These children may have physical developmental
delays
and will likely need extra support. Some children will need a heart transplant to
survive into adulthood. They will also need regular follow-up care at a center
specializing in this type of congenital heart care.
In
the long term, children with HLHS have an increased risk for complications such as
heart
failure and heart rhythm problems. They are also at risk for digestive and liver
problems. Children with HLHS after surgery often have lower exercise tolerance.
Discuss your child's specific outlook with the healthcare provider.
When to Call a Healthcare Provider
Call your child's healthcare provider if your child's symptoms get worse or if new
symptoms develop.
Key Points
- Hypoplastic left heart syndrome is a group of problems that affect the heart and large
blood vessels.
- Babies usually get symptoms shortly after birth.
- Babies
with HLHS need surgery to survive.
- Most
babies will need a series of surgeries during their first 2 to 3 years of life.
- After
the surgeries, children will need special care and to be monitored for
complications.
Next Steps
Tips to help you get the most from a visit to your child’s healthcare provider:
- Know the reason for the visit and what you want to happen.
- Before your visit, write down questions you want answered.
- At the
visit, write down the name of a new diagnosis and any new medicines, treatments, or
tests. Also write down any new instructions your provider gives you for your
child.
- Know why a new medicine or treatment is prescribed and how it will help your child.
Also know what the side effects are.
- Ask if your child’s condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if your child does not take the medicine or have the test or procedure.
- If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
- Know
how you can contact your child’s provider after office hours. This is important if
your child becomes ill and you have questions or need advice.