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Learning About Hypoplastic Left Heart Syndrome in Newborns

Normal heart and heart showing smaller aorta and smaller left ventricle (hypoplastic left heart) along with the ductus arteriosus

What is hypoplastic left heart syndrome?

Hypoplastic left heart syndrome is a type of congenital heart disease. Congenital heart disease refers to heart problems a baby is born with. These heart problems are usually diagnosed at or before birth.

"Hypoplastic" means "not developed." A "syndrome" is a group of problems. So hypoplastic left heart syndrome is a group of problems caused when the baby's heart hasn't grown the way it should. The main problem is that the structures on the left side of the heart are much too small.

In a normal heart, the left ventricle takes in oxygen-rich blood (red blood) from the lungs and pumps it out through the large blood vessel called the aorta and out to the body. The right ventricle takes in oxygen-poor blood (blue blood) from the body and pumps it to the lungs to get oxygen.

In hypoplastic left heart syndrome, the left ventricle and the aorta are both too small. So the right ventricle has to take over and do both pumping jobs.

Most babies with this problem also have an atrial septal defect. This is a hole in the wall between the left and right sides of the heart. Some of the blood flows through the hole. So too much blood goes to the lungs and not enough red blood goes to the body.

The baby's body is still able to get some oxygen because of a small blood vessel that connects the left and right sides of the heart. This blood vessel is called the ductus arteriosus. It is part of the circulation system before birth. It usually closes shortly after birth. Medicine can keep it open for a while. The opening lets red blood mix with blue blood so that at least some oxygen goes out to the baby's body.

Your baby will need special care, such as being in the neonatal intensive care unit (NICU). This may be scary for you. But the hospital staff understands this. They will explain what happens and will answer your questions.

How is it diagnosed?

Your doctor may hear abnormal heart sounds, such as a heart murmur, when examining your newborn.

Your doctor will order tests to find the cause of abnormal sounds or of symptoms. The most common test used to identify this problem is called an echocardiogram, or "echo" for short. It uses sound waves to make an image of your baby's heart.

Other tests, such as an EKG (electrocardiogram), chest X-ray, and checking the amount of oxygen in the blood, also help identify the problem.

A fetal ultrasound, which looks at the baby's heart, may find this problem before birth.

What are the symptoms?

The heart is not pumping well, so a baby may get very sick soon after birth because there is not enough blood being pumped out to the body. Symptoms include fast breathing and a blue tint to the skin, lips, or fingernails.

How is it treated?

Deciding what treatment is right for your baby can be very hard. Your doctor will help you understand your choices and what to expect from each choice.

Your baby may get medicine to keep the opening between the left and right sides of the heart open. This helps keep red blood flowing to the body and helps prepare your baby for surgery. The medicine may be given through a blood vessel. It is often given through the belly button.

If there is no opening between the left and right sides of the heart, your doctor may do a treatment to create one. This treatment is called catheterization. The doctor puts a thin tube into a blood vessel in your baby's groin. This tube is called a catheter. The doctor moves the catheter through the blood vessel to the heart. The doctor moves special tools through the catheter to the heart to create the hole. Your baby will be asleep during this treatment.

A series of surgeries may be done to help the baby's heart work better. The first surgery is usually done shortly after birth. A second surgery may be done a few months later. If a third surgery is planned, it is done when the child is about 2 to 5 years old.

The main goal of the surgeries is to reroute some of the blood vessels around the heart. That will make the right ventricle the main pumping chamber of the heart, instead of the left ventricle. This will not make the heart work like a normal heart. But it will help the heart get red blood to the body.

If you and your doctor decide not to do surgery, your doctor may suggest other treatment to help your baby's symptoms and keep your baby comfortable.

What can you expect?

  • You may see tubes and wires attached to your baby. This can be scary to see. But these things help the doctor treat your baby. The tubes supply air, fluid, and medicines to your baby. The wires are attached to machines that help the doctor keep track of your baby's vital signs. These include temperature, blood pressure, breathing rate, and pulse rate.
  • If your baby has trouble breathing, the doctor may use a ventilator. This machine helps your baby breathe. To use the machine, the doctor puts a soft tube through your baby's mouth into the windpipe.
  • The hospital staff will give your baby the nutrition that your baby needs. The doctor may feed your baby through a soft tube that goes through the nose and into the stomach. Or the doctor may use an I.V. that goes through the belly button to do this.
  • Your baby may need oxygen. It is given to the baby through a tube in the nose or throat.
  • Your baby will be kept comfortable and warm.
  • It may seem that your baby is getting lots of tests. All of these tests help your doctor keep track of your baby's condition and give the best treatment possible.
  • It's hard to be apart from your baby, especially when you worry about your baby's condition. Know that the hospital staff is well prepared to care for babies with this condition. They will do everything they can to help. If you need it, ask for support from friends and family. You can also ask the hospital staff about counselling and support.

Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if your child is having problems. It's also a good idea to know your child's test results and keep a list of the medicines your child takes.

Where can you learn more?

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