Growth Charts
Possible Newborn Health Problems
Heart Defects
Gastro-intestinal Tract Disorders
Duodenal Atresia
Hirschsprung's Disease
Imperforate Anus
Tracheo-oesophageal Fistula
Congenital Cataracts
Unusual Blood Results

Heart Defects

Symptoms
Treatment
Outcomes

How are heart defects discovered?
• Sometimes a heart defects is suspected because a baby is breathless or sweaty or a murmur is heard.

• Sometimes a baby with Down syndrome may seem perfectly well but still have a major heart defect, which can lead to serious problems if not treated.

• This means it is very important that all our babies have their hearts carefully checked soon after birth by a paediatrician’s examination and by an echocardiogram.

•An echo is very similar to an ultra-sound scan like those performed in pregnancy and gives a moving picture of your baby’s heart.

• The echo will show if your baby has a heart defect and your paediatrician will decide if further tests are needed or if your baby needs to be referred to the heart unit in Auckland.

How do heart defects occur?
• A defect occurs when a baby’s heart starts to develop in the usual way but does not develop fully. It may help to reread the section on usual development.

• If the problem happens at birth then the baby may have a patent ductus arteriosus.

• If the problem happens in early pregnancy then part of the central heart structure will be missing and the baby will have a septal defect or ‘hole in the heart’. This can be an atrial septal defect, a ventricular septal defect or an atrioventricular septal defect.

What do our babies’ echos show?
• 55% have a healthy heart with no defect

• 20% have an atrioventricular septal defect (AVSD)

• 10% have a ventricular septal defect (VSD)

• 15% have another defect, often a patent ductus arteriosus (PDA) or an atrial septal defect (ASD)

What is a Patent ductus arteriosus (PDA)?
• A patent ductus arterious occurs when the blood vessel between the aorta and main pulmonary artery (that all babies require before birth) fails to close at birth.

• It is a very common problem in premature babies.

Why do septal defects occur?
• Septal defects occur when a baby’s heart development is interrupted early in pregnancy.

• There are problems with the development of the central structures of the heart from the endocardial cushions.

• Defects (holes) can occur in any of these structures (the atrial septum, the ventricular septum and the valves between the atria and ventricles).

What is an atrial-septal defect (ASD)?
• An ASD is a defect (hole in the heart) in the atrial septum between the receiving chambers of the heart, the left and right atria.

What is a ventricular septal defect (VSD)?
A VSD is a defect (hole in the heart) in the ventricular septum between the pumping chambers of the heart, the left and right ventricles.

In our babies the VSD is usually in the part of the septum nearest the mitral and tricuspid valves so may be called a VSD of the AV canal type.

What is an Atrioventricular septal defect (AVSD)?
An AVSD can also be called
• an atrioventricular canal defect (AV canal) or
• an endocardial cushion defect

There are three types of AVSDs.
• complete AVSD
•partial or incomplete AVSD
• transitional AVSD

- Complete AVSD
a complete AVSD has three abnormalities

• a defect (hole in the heart) in the atrial septum between the receiving chambers of the heart, the left and right atria

• a defect (hole in the heart) in the ventricular septum between the pumping chambers of the heart, the left and right ventricles

• just one ‘common’ AV valve instead of separate mitral and tricuspid valves.

- Partial or incomplete AVSD
a partial AVSD has three abnormalities less severe than those of a complete AVSD
• an ostium primum atrial septal defect (a small hole in the heart between the receiving chambers of the heart, the left and right atria).

• a small defect (hole in the heart) in the ventricular septum between the pumping chambers of the heart, the left and right ventricles.

• usually a cleft in the mitral valve that may cause the valve to leak.

- Transitional AVSD
a transitional AVSD looks similar to a complete AVSD but behaves like a partial AVSD.

The leaflets of the common AV valve are stuck to the ventricular septum making it seem like there are two valves and no VSD.

Symptoms

Why do heart disorders cause problems?
• Septal defects and PDAs can cause problems because they allow blood to cross from the left hand side to the right hand side of the circulation.

• This is called a left-to-right shunt.

• Blood shunts from left to right because the pressure in the left ventricle is much higher than the pressure in the lungs.

• The severity of problems increases with
- the amount of blood shunted and
- increasing pressure in the vessels of the lungs.

What problems can occur?
In order of severity problems are

•None

• Poor growth with no other problems

• Congestive heart failure

• Pulmonary hypertension

Which babies get no problems?
• If only a little blood is shunted, the body copes easily and no problems are seen. This may occur in babies with
- partial ventricular septal defects
- atrial septal defects
- a small patent ductus arteriosus

Which babies just get poor growth?
• Poor growth with no other problems can occur in babies with
- atrial septal defects,
- partial atrioventricular septal defects,

• The left-to-right shunt occurs between the atria rather than the ventricles, so pressure from the left ventricle is not passed on to the lungs.

• The lung pressure is not high so the baby is unlikely to develop the more serious problems of congestive heart failure or pulmonary hypertension

• But, the heart is still working harder than usual to push extra blood through the lungs

• Some of the baby’s energy supply (food) must be used for the heart to do this extra work so less is available for weight gain, and growth may occur more slowly than in other babies.

Which babies get congestive heart failure?
Congestive heart failure can occur in babies with
- complete atrioventricular septal defects
- large ventricular septal defects
- a large patent ductus arteriosus
- partial atrioventricular septal defects with very leaky mitral valves

What causes congestive heart failure?
Congestive heart failure (CHF) is a combination of increased heart and lung work because

• the left side of the heart works very hard
With each push most blood shunts to the right side of the heart with only a little going to the body.

To get enough blood into the body, the heart has to push out two to three times more blood than normal.

High pressure is passed on from the left ventricle to the lungs

• too much blood goes to the lungs
The vessels of the lungs are so full of blood that fluid leaks from them into the air
spaces of the lungs, making them congested.

This is called pulmonary oedema and makes it hard for the lungs to work.

What problems does congestive heart failure cause?
Babies with congestive heart failure may

• be small

• look unwell.

• breathe faster than usual and use more of the muscles of their chest and abdomen to help them breathe

• have fast heart rates, even when asleep.

• have hearts that pump so hard you can easily feel and see the heart beat on their chests

• be sweaty

• be sleepy and tire easily

• have feeding problems and poor weight gain

•often get chest infections

Each baby is different and will have a different mixture of problems.

When does congestive heart failure develop?
• Congestive heart failure does not usually occur as soon as the baby is born.

• This is because the pressure in the lungs is high when babies are first born so less blood shunts from left to right.

• Symptoms gradually appear after two to three weeks as the pressure in the lungs begins to fall and more blood flows through the heart defect.

Which children get pulmonary hypertension?
Pulmonary hypertension occurs rarely in children with

• complete atrioventricular septal defects

• large ventricular septal defects

What causes pulmonary hypertension?
• Pulmonary hypertension only occurs in conditions where there is a large heart defect so that high pressure can be transmitted from the left ventricle to the lungs.

• In some babies with these severe heart defects, the muscles around the small pulmonary arteries to the lungs get bigger and constrict. This is to try to protect the lungs from the extra blood flow and pressure passed on from the left ventricle.

• This is called pulmonary hypertension and seems to happen more easily in babies with Down syndrome than in other babies.

What problems does pulmonary hypertension cause?
• When the vessels constrict, there is less left-to-right shunting, and so less signs of congestive heart failure.

• Although this may mean that at first a baby appears healthier, it is not a good sign.

• Over time the muscles thicken permanently, which cannot be cured.

• The pressure in the lungs rises. After a few years, the pressure in the lungs may become so high that it is greater than that in the left ventricle

• This means blood no longer shunts left to right, but instead right to left. This is called Eisenmenger’s syndrome.

• Deoxygenated blood from the right side of the heart can now go to the body and this gives the skin a bluish tinge called cyanosis.

• Not enough oxygen reaches the body so the child gradually becomes more and more unwell and usually dies as a teenager or young adult.

Treatment

If it is possible to wait a few months or years, then

• the baby’s heart grows bigger
if surgery is needed, it is easier with a bigger heart

• the defect may close or get smaller by itself

Atrial septal defects
About half of ASDs will close themselves within the first 18 months of life so need no treatment

Ventricular septal defects
VSDs sometimes get smaller or close completely in the first year of life, if this happens a baby may not need surgery.

Patent ductus arteriosus
A PDA will often close by itself in the first month of life and need no treatment.

Atrioventricular septal defects
AVSDs never close by themselves and will always need open-heart surgery.

Waiting for surgery
You may be given a particular age or weight your baby needs to reach before having surgery, this is often about ;

• 3-6 months for babies with a complete atrioventricular septal defect

• 6-18 months for babies with a ventricular septal defect or partial atrioventricular septal defect

• 2-4 years for children with an atrial septal defect

If during this time your baby develops congestive heart failure, treatment with medicines may be tried.

If the medicines aren’t helping or if the pressure in the lungs is becoming high surgery will be needed more urgently.

Help with feeding
• To help babies gain weight, special high calorie powders may be added to their milk

• The milk may be given directly to a baby’s stomach through a nasogastric tube so the baby does not have to use up energy by sucking.

Medicines
Prophylactic antibiotics
• Prophylactic antibiotics are antibiotics given to a child who is well to prevent endocarditis.

• If children with heart defects have an operation or dental treatment, bacteria may enter their blood.

• A clump of bacteria may stick to the heart defect and cause endocarditis; a serious infection of the lining of the heart that can be fatal.

• Endocarditis will not occur if antibiotics are given before the operation or dental treatment.

Medicines for congestive heart failure
Frusemide (lasix), or another diuretic is often the first medicine given diuretics remove extra fluid from the lungs, by making a baby pass more urine

Captopril or another medicine for lowering blood pressure may be used. The heart has less work to do when it pumps against a lower pressure

Digoxin may be used to help the heart pump blood more efficiently.

Medicine for patent ductus arteriosus
• In a newborn with a patent ductus arteriosus, a drug called Indomethacin can be given.

• This drug helps to constrict the muscle in the wall of the patent ductus arteriosus to close it.


Surgery
•Patent ductus arteriosus
If a patent ductus arteriosus is still present beyond the newborn period, it will generally never close on its own; The ductus is tied off, a more minor procedure than open-heart surgery.

• Atrial septal defects
Some atrial septal defects may be closed without open-heart surgery. A device is inserted through a large vein into the heart and attaches to the tissue around the atrial septal defect to fill the hole.

Open-heart surgery
Atrial septal defects may have the hole directly closed with sutures or may need to be closed with a patch.

Ventricular septal defects need to be closed with a patch.

Atrioventricular septal defects have the septal defects closed with patches, and the common atrioventricular valve reconstructed. The hardest part of the surgery is dividing this single valve into two.

• Open-heart surgery is performed at the heart unit of Starship hospital, Auckland

• After open-heart surgery a baby spends around two days in intensive care and up to ten days in hospital.

Outcomes

Will my baby survive the operation?
Survival figures have improved dramatically over the past years and it is now extremely rare (under 1%) for a baby to die during surgery or immediately afterwards.

What will life be like afterwards?
Most heart defects are repaired completely and have no further influence on a child’s life. Children may need

• Follow-up visits with the cardiologist to assess heart function

• Continued antibiotic prophylaxis for endocarditis

What about complete AVSDs?
• Repair of a complete atrioventricular septal defect is often more complex especially if the lung pressure is high

• Babies with these defects may have extra problems:

They may need a longer time on a ventilator and more medicines after surgery

They may still have heart problems following surgery
- The opening in the mitral valve may now be too narrow or still be very leaky.

- There may be narrowing of the path for blood to pass from the left ventricle to the aorta

- The specialized tissue that conducts the impulse for the heart to beat runs very near the area where the stitches for the ventricular patch need to be placed. If this is disrupted, placement of a pacemaker may be necessary

• About 10% of these children will need further surgery later.