Children with complex heart conditions can be offered a variety of treatments and interventions to improve their heart function. On the following pages a number of different treatments are described.

It is important to remember that not all of them will be appropriate for every child and that in many cases they are staged through a child’s or young adults life.



These are drugs that lengthen the time it takes for the blood to clot. They are used to ensure that the blood flows freely through the tubes and passages that have been created in the heart.

Aspirin is a gentle anticoagulant that stops blood cells sticking together. It is often the drug of choice in young children.

Warfarin is a medication that slows down the blood’s ability to clot (form scabs). Regular blood tests are required to ensure that the correct dose of Warfarin is given.

Dipyridamole works to interrupt the formation of clots.

Clopidogrel works to hinder the formation of clots. It sometimes replaces Aspirin or can be used in partnership with Aspirin.

For more information see LHM’s Living with Anticoagulation booklet.

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Arrhythmias and pacemakers

Heart rhythm

All hearts have a heartbeat, which is the electrical message that passes through the heart and tells the heart muscle to push blood from one section of the heart to another and then out of the heart to the circulation. The beat (pulse) created depends on the body’s activity, so at rest the rate is lower and on exercise it becomes faster. Children and adults with congenital heart conditions may have a disturbed heart rhythm (arrhythmia). Sometimes they are born with an arrhythmia, sometimes one develops.

Many children who have had major heart surgery have a disturbed heart rhythm after their operations. These are usually temporary and are solved as the heart recovers from the surgery but in some cases the heart rhythm does not recover and a more permanent solution will need to be found. The first treatment offered will often be medications to control the heartbeat. This may solve the problem and no further intervention will be needed. For some children and young adults other solutions will be explored.

Ablating an electrical pathway

In some patients the electrical pathway will be disturbed so that heart rhythm messages will be sent to the wrong part of the heart, which creates an imbalance with the pumping of the heart muscle. In these cases cardiologists may offer ablation as a treatment. This is a treatment undertaken under anaesthetic in the cardiac catheterisation theatre. Cardiologists identify the pathways of faulty electrical activity and block the ones that are creating an imbalance. This may be done by either a freezing or burning process.


If an arrhythmia (abnormal heart rhythm) persists and affects the heart function doctors may decide to insert a pacemaker. There are a number of different pacemakers that solve different problems. Some help to regulate the heartbeat, others send an impulse to the heart when there are long pauses between beats. Surgery will be needed to insert the pacemaker but it is not as complex as open heart operations. The pacemaker box is either placed in the abdomen, especially in smaller children, or under the arm or chest muscles in an older/bigger patient.

Following a pacemaker insertion regular pacemaker checks will be set in place. Changes to the pacemaker settings can be made externally so there is no need for further invasive intervention until the pacemaker box needs changing – usually at around ten-year intervals.

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Ballooning valves and arteries

Children who have malformations within the heart requiring reconstruction of blood vessels often develop a narrowing around the site of surgery or the malformation. To ensure that blood can flow freely through the blood vessels cardiologists often balloon the area of the narrowing to stretch it back to normal or nearly normal size. The ballooning takes place during a cardiac catheterisation (see Cardiac Tests below). Most children have this procedure done under a light anaesthetic and they will be in hospital for an overnight stay.

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Cardiac tests

Oxygen saturation

This is a simple painless test where a plastic strip or clip is attached to a finger or foot to measure the amount of oxygen circulating in the blood of babies, children and adults. It is particularly important for children with complex heart conditions who are blue (cyanosed) because of the low oxygen levels as it helps the medical team to plan their treatment and care.

Blood tests

Blood is a very important part of the circulation because it carries all sorts of things around the body: oxygen, nutrients and chemicals. Taking samples of blood can be a very helpful way of monitoring how well a baby, child or adult is and how the body is coping with an illness or long-term condition.

Chest X-rays

For doctors to see if a baby, child or adult’s chest is healthy, especially before and after surgery, the easiest test is to take an x-ray of the chest so that they can see how the chest is healing but also to look for infections or fluid collections in the lung area. These tests help plan treatment and post-surgery recovery support.

Echocardiogram (Echo)

Echocardiography uses sound waves to scan the heart which is then shown as a picture. This is the same type of scan that mothers have during pregnancy. The test does not hurt, but children sometimes have a light sleeping medicine (sedative) so that they stay still. This is the first test that will be done on the baby, as it is the easiest and least stressful way of making a diagnosis of congenital heart disease.


Electrocardiography (ECG) is the recording of the electrical activity of the heart. The heart has its own electrical system, which passes the message to beat through the heart’s muscle tissue. Sometimes the message breaks down and so by recording the rhythm, the medical team can see if the messages are being passed properly. It is also possible to assess the size of the pumping chamber and the thickness of the heart wall.

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Cavo-Pulmonary Connection (Stage Two) for all single ventricle conditions

Bi-directional Cavo-Pulmonary Shunt (Glenn Shunt) or The Hemi-Fontan Operation




As the children grow, they will require a more permanent supply of blood to their lungs than earlier surgical procedures can provide. A Cavo-Pulmonary Connection is normally performed between three and twelve months of age.

The aim of this operation is to redirect the flow of blue blood (deoxygenated blood) to the lungs by attaching the upper body vein (superior vena cava) directly on to the lung artery (pulmonary artery). The Gore-Tex shunt or band that was inserted at the last operation will be taken away.

In some centres the stump of the lower body vein (inferior vena cava) is attached to the base of the lung artery (pulmonary artery). This is known as the Hemi-Fontan operation. Although blood does not flow through this attachment at this time, it prepares the child for the completion of a Fontan procedure at Stage Three.

These operations have fewer risks than the first stage but it is important to talk with the medical team to find out the risks for your child.

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Children who are born with complex congenital heart disease associated with a reduced blood flow to their lungs can sometimes develop collateral vessels.

What are collaterals?

If a baby is born with a malformation of the heart and a lack of blood flowing to the lungs to collect oxygen, the child will have low oxygen saturations (the amount of oxygen in their blood). They will be cyanosed (have blue-coloured lips and fingernails) and may be breathless on mild exercise or feeding. Collaterals are connections, like normal blood vessels, that can develop in children with cyanotic heart disease such as single ventricle heart conditions.

There are two types of collaterals:

Systemic Arterial Collaterals




These abnormal vessels originate from the body blood vessels, in particular the aorta, and grow towards the lungs. They can form when a child has had a long period of cyanosis (low oxygen levels in the blood which create blue lips and fingernails). The collaterals aim to take more blood to the lungs where it can collect oxygen. This is the body’s response to the long-standing low oxygen saturations. These collaterals make the child less blue but create more work for

Systemic Venous Collaterals




These are abnormal blood vessels that originate from the veins taking the blue (deoxygenated) blood back to the heart. They normally develop after the second operation, the Cavo-Pulmonary Connection (or Stage Two). After this operation the pressure in the veins in the upper body is greater than the pressure in the veins in the lower body. With that, small veins can enlarge and can allow blue (deoxygenated) blood from the upper body to run down to the lower body rather than having to squeeze through the lungs. These collaterals make the child more blue, but do not increase the work for the heart.

How are collaterals diagnosed?

When children with single ventricle disorders undergo cardiac catheterisation or MRI scanning investigations it is possible to clearly see the collateral vessels. When there is a large collateral vessel it may be seen during a routine scan (echocardiogram). (See Cardiac tests above).

How are collaterals treated?

Once collateral vessels have been found the cardiac team will assess if they need closing (occlusion). Small systemic arterial collaterals will normally disappear after the Fontan procedure has been performed. Large systemic arterial collaterals should normally be closed by a catheter procedure as they put strain on the heart and raise the pressure in the lung arteries. The child may be more cyanosed after this, and the Fontan operation may have to be performed earlier.

Large systemic venous collaterals in young children after the Cavo-Pulmonary Connection operation (Stage Two) should be closed by catheter. This will make the child less cyanosed, as more blue blood goes to the lungs, and frequently the Fontan operation can be delayed. Small systemic venous collaterals identified just before the Fontan operation can be ignored.

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The Damus Procedure



Children who are born with only one of the chambers (ventricles) needed to pump blood around their body and who may also have a narrowing of the body artery (aorta) may need to have surgery to aid circulation of blood from the heart to the body.

The base of the lung artery (pulmonary artery trunk) is attached to the base of the body artery (aorta) to ensure that all the blood that enters the one functioning pumping chamber will be directed around the body.

To ensure that blood also reaches the lungs a connection (shunt) is made between the body circulation and the lung artery (pulmonary artery).

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Dental care and sub-acute bacterial endocarditis

Good dental hygiene is extremely important for children with single ventricle heart conditions. The reason it is even more important for these children is that they are at an increased risk of something called endocarditis (a very serious infection of the inner lining of the heart), which is explained below. Always tell your dentist about your child’s heart condition and any medications he or she takes, especially anticoagulants such as Warfarin or Aspirin.

What is endocarditis?

We all have small bugs that live in our mouths and on our skin; they cause us no harm at all until we get gum disease (gingivitis/periodontitis) or a bad or broken tooth, or a skin injury which becomes infected. For most of us, this would mean a course of antibiotics and we would then be fine, but if you have congenital heart disease it can be more serious.

The bugs that infect our mouths can get into the blood stream and attach to the areas in the heart where surgery has been performed. The bugs then grow and cause the heart to become infected; this is called infective endocarditis. If this should happen, the only way to cure the infection is a four – to six-week course of intravenous antibiotics. If this goes untreated your child would become sicker and sicker. Skin infections would need to be treated equally swiftly.

How should I look after my child’s teeth?

Ask your dentist if you would like any extra advice about looking after your child’s teeth.

Dental treatment, antibiotics and endocarditis

In 2008, new guidelines were published on the prescribing of antibiotics for dental treatment (and reviewed in 2016).

NICE, the government organisation that rationalises medical treatments, has researched the use of antibiotics during dental treatment. Its recommendations are that very few congenital heart patients need antibiotics as a preventive measure (sometimes referred to as ‘antibiotic prophylaxis’ by doctors and dentists) during dental and skin treatment, however, there may be some occasions when a dentist or cardiologist may choose to prescribe antibiotics for an individual patient.

Baby teeth naturally falling out should not pose any risk to your child.

Do cardiac medications have any impact on dental care?

Most children with single ventricle heart conditions take anticoagulants such as Warfarin or Aspirin. As these medications make it more difficult for blood to clot, some dental procedures, such as having a tooth removed, could cause more bleeding than in another child.

Remind your dentist about these medications before any dental treatment begins. He or she might ask for your child to have an extra blood test (INR) the day before the procedure. If you have a home testing kit (CoaguChek machine), it would be really helpful to your dentist if you can take an INR reading on the morning of the procedure.

Planning dental procedures early in the morning is sensible, so that you can easily get help if any complications such as unexpected bleeding happen later in the day.

The NHS National Patient Safety Agency states that an INR of four or less can be safely managed in a standard dental setting. Your dentist will know what extra precautions are needed (e.g. special packing or extra stitches if a tooth is taken out).

Your dentist will advise you how to care for your child’s mouth after any treatment. The advice will cover areas such as resting, being very careful as the blood clot forms, and what to do if bleeding starts again. Regular Paracetamol may be advised as a form of pain relief. Unless you are told otherwise, avoid taking medicines like Ibuprofen or Aspirin at the same time as Warfarin.

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ECMO or ECLS (Extracorporeal Membrane Oxygenation or Extracorporeal Life Support)

Extracorporeal Membrane Oxygenation or Extracorporeal Life Support

Babies and children with congenital heart conditions sometimes have periods of time when they have difficulty pumping enough oxygen-filled blood around their body. This may be because their heart is failing as they await surgery or in the period after an operation when their heart is tired. If doctors feel that a period of added support for the heart will aid recovery they may suggest ECMO.

The ECMO machine is similar to the heart-lung bypass machine used for open heart surgery, although often smaller. Extracorporeal means ‘outside the body’, and a membrane oxygenator is a piece of equipment which delivers oxygen into your child’s blood.

Therefore, ECMO is the use of an artificial lung (membrane) located outside the body (extracorporeal) that puts oxygen into the blood (oxygenation) and continuously pumps this blood into and around the body.

Most congenital heart units are able to offer ECMO for cardiac patients but occasionally a child will be transferred to another cardiac team for the specialised care.

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The Fontan Procedure (Stage Three) for all single ventricle conditions or completion of the Cavo-Pulmonary Connection

The final stage of surgery will be performed as the child starts to show that they need more blood flow to the lungs. They may become more breathless on exercise or their growth may slow down. For some children this will occur before they start school. Others may be able to wait a little longer. For more information see the LHM booklet The Fontan.

The Fontan procedure aims to separate the blue (deoxygenated) blood supply and the red (oxygenated) blood supply. Although this does not make the heart function normal, it does allow the children to grow and enjoy more physical activity. The procedure can be performed in two ways.

External Fontan or External Conduit




This operation is done by attaching a tube of a special plastic (a conduit of Gore-Tex) from the lower body vein (inferior vena cava) to the base of the lung artery (pulmonary artery), diverting blue (deoxygenated) blood away from the heart straight to the lungs.

A hole (fenestration) may be created between the tube and the right collecting chamber (right atrium). As with the Internal Fontan (see below) there can be a rise in pressure in the lung arteries after surgery and the hole acts as a pressure valve.

Children may be in hospital for some weeks after the third operation as it is important to give them time to adjust to their new circulation.

Internal Fontan




This is done by creating a wall (baffle) in the right collecting chamber (right atrium) and then attaching the chamber to the base of the lung artery (pulmonary artery). This may have been partially completed at stage two, the Hemi-Fontan.

All the returning blue (deoxygenated) blood will now be flowing to the lungs, without a pump behind it. This causes an increase in pressure within the lung blood vessels, so, to aid circulation, a small hole (fenestration) may be created in the wall (baffle). This acts as a pressure release valve whilst the child’s body adjusts to the new circulation.

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Many families who have a child with congenital heart disease ask why their child was born with the condition. In some cases the malformation will have occurred because of a genetic problem that has affected the heart as it formed in the womb.

A blueprint

When a new house is built the architect draws up a plan of what the house will look like and how it is going to be built.

When a new child is being created, information is drawn from the mother and the father to make a plan of how the child will look and how its body will be put together to work.

A genetic blueprint

Every person in the world has a genetic blueprint of their own. The blueprint is stored in every cell in their body and holds the information required to help the body grow, develop and work properly. The information is made up of lots of messages which we call genes. We have about 30,000 genes in each cell of our body. Different genes have different messages that are responsible for instructing our body to do specific things. For instance, genes determine the colour of our hair or eyes or how cells work in different organs, for example, the liver, heart or lungs. It is our very own information computer.

The genes are stored in coils and split into chromosomes. Humans have 23 pairs of chromosomes, so 46 in total. 23 chromosomes (one of each pair) come from the mother and the other 23 from the father. They are transferred in the egg and the sperm that make a child.

The picture below shows what the chromosomes look like – if you look at the last set of chromosomes in this picture you will see that they are labelled X and Y. These are the chromosomes that decide if you are male or female. The chromosomes below must come from a man because there is an X and a Y chromosome. A woman has two X chromosomes.


Genetics and heart disease

Some congenital heart conditions are linked to a genetic disorder such as Down’s syndrome or 22q Deletion. These disorders are caused when one of the 46 information chromosomes is malformed. As the baby grows in the womb, the genetic malformation will cause a particular part of the heart to develop incorrectly. In some cases the genetic condition can be detected before birth.

Geneticists (genetics doctors) are always looking for genetic causes for congenital conditions; however, there are many heart conditions that do not have a specific genetic cause. Many of the single ventricle heart conditions fall into this group.

There may be many factors, as yet unknown, that cause a baby’s heart to develop abnormally. The problems can occur early in pregnancy as the heart forms or later as it grows.

Congenital heart conditions occur in 1 in 100 pregnancies. If you have previously had a child with a single ventricle heart problem, the risks of it happening again to parents, their other children or the child affected themselves rises to between 5 and 8%. Although the risk is higher, over 90% of future babies will not have a problem with their heart.

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Heart failure

This is a commonly used term, which means that the heart is failing to do its job properly. It can occur:

  • if a child has a congenital heart defect
  • following surgery as the heart is healing
  • as the heart muscle grows tired because it has to work too hard.

It means that the heart muscle is unable to pump blood around the body efficiently, often leaving fluid in the body tissues (e.g. the lungs and liver).

Signs and symptoms of heart failure:


Especially when feeding or taking exercise.

Poor feeding

Because the heart is working hard, eating and drinking become hard work.


Because all the child’s energy is being used to keep the heart working.

Puffiness (oedema)

Especially around the eyes, because fluid is not being passed around the body properly.

Small amounts of urine

Because fluid is not moving around the body to the kidneys.


Because the child feels unwell or uncomfortable.

If your child is showing any of the above signs, especially when feeding or taking gentle exercise (e.g. walking), contact your local doctor. It may be that your child has a simple cold but it is always important that someone assesses your child.

If the child is very tired and not completing feeds it may be necessary for them to have a short stay in hospital and some help with feeding. Medications are also given to help the heart function and to help the child pass more urine.

This treatment will give the heart an opportunity to rest and recover. (See Medications). Most children are able to live at home on medication once their condition has stabilised.

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The Hybrid Procedure



In the past many newborn babies were not suitable for the Norwood Procedure for Hypoplastic Left Heart Syndrome because they were too small or too sick. Medical teams have been working to develop a procedure that will support a newborn baby’s heart until he or she is big enough to undergo more complex reconstructive operations. This procedure is called the Hybrid Procedure.

For some babies born with a diagnosis of Hypoplastic Left Heart Syndrome, the Norwood Procedure, the first stage of surgery, may not be possible or may have an exceptionally high risk.

The Hybrid Procedure has been developed as a way to help a baby survive until it is strong enough and big enough for the more complex Norwood Procedure.

The aim of the Hybrid Procedure is to allow flow of oxygen-filled red blood (oxygenated blood) to reach the body and to allow used blue blood (deoxygenated blood) to reach the lungs where it can collect oxygen again.

This is done by keeping open the arterial duct and holes that are in the heart whilst the baby is still inside the womb (fetal circulation), at the same time protecting the lung blood vessels so that they can still be used in later surgery. (See Fetal Circulation).

The Hybrid Procedure is performed under a general anaesthetic within the cardiac catheter suite or the operating room or possibly both.

The procedure is performed by both a cardiac surgeon and a cardiologist.

There are three parts to this procedure:

  1. Small bands are tightened around the left and right lung arteries (pulmonary arteries) to control the flow of blood and pressure in the lungs.
  2. A mesh of fine metal (stent) is placed in the patent ductus arteriosus (between the pulmonary arteries and the aorta) to keep it open.
  3. At the same time the hole between the upper collecting chambers (atria) may be made bigger and permanent (atrial septostomy). This may be delayed for about a week.

This procedure has less initial risk than the original Stage One Norwood Procedure but children undergoing the Hybrid Procedure are usually sicker or smaller so their personal risks may be high.

Children who have undergone the Hybrid Procedure will need a more complex operation at Stage Two that will incorporate the reconstructive surgery of the usual Stage One Norwood Procedure as well as the Stage Two Cavo-Pulmonary Connection.

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Inserting a stent

Following the ballooning of a blood vessel it may be necessary to insert a stent (a mesh of fine wire in a tube shape) that can be used to keep the blood vessel open after it has been stretched. This is inserted during a cardiac catheterisation.

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A very important part of the treatment of complex congenital heart disease is the medical support given to the heart and circulation. This support will be altered as the needs of each child and young adult change as they undergo surgery and grow. Part of the ongoing maintenance of stable heart function will include prescribing medications.


Diuretics are medications that make the kidneys work more efficiently to create urine from the fluid circulating in the blood. The more fluid in the blood, the harder the heart has to work to pump it around the body. It is important to encourage children to continue drinking normally whilst on these medications.

Frusemide (Furosemide)is the most commonly used diuretic; it works well in all age groups.

Amiloride is often used as it keeps the body’s salts (electrolytes) in balance as the child passes out more urine.

Spironolactone is another form of diuretic.

On some occasions these medications are used together.

Medications that strengthen or support the heart’s function

Digoxin is a drug that slows, strengthens and steadies the heart. It is often used in the treatment of heart failure as it makes the heart beat more efficiently.

Captopril, Lisinopril, Ramipril and Enalapril – ACE inhibitors are medications that open up the body’s blood vessels, making it easier for the heart to pump blood through them. This relieves pressure/workload on the heart pumps (ventricles).

Carvedilol is a drug that slows down the resting heart rate and increases the efficiency of the heart muscle.


These are medications that help a heart that is not beating in rhythm. These drugs strengthen the heartbeat and make the beat more regular.

Digoxin is a drug that slows, strengthens and steadies the heart. It is often used in the treatment of heart failure as it makes the heart beat more efficiently.

Amiodarone helps treat heartbeats that are irregular by blocking some defective electrical signals. Avoid eating grapefruit if prescribed this medication because it alters the function of Amiodarone.

Sotalol is prescribed to block irregular electrical messages as they pass through the heart. This steadies the heartbeat.


These are drugs that lengthen the time it takes for the blood to clot. They are used to ensure that the blood flows freely through the tubes and passages that have been created in the heart. For more information see the LHM booklet Living with Anticoagulation.

Aspirin is a gentle anticoagulant that stops blood cells sticking together. It is often the drug of choice in young children.

Warfarin is a medication that slows down the blood’s ability to clot (form scabs). Regular blood tests are required to ensure that the correct dose of Warfarin is given.

Dipyridamole works to interrupt the formation of clots.

Clopidogrel works to hinder the formation of clots. It sometimes replaces Aspirin or can be used in partnership with Aspirin.

Anti-Pulmonary Hypertensives

Sildenafil works to relax blood vessels so that they widen more easily, making it easier for the heart to push blood through them.

Dipyridamole works to reduce blood pressure by opening up blood vessels. It works especially well in the lungs.

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MCT diet

The MCT (Medium Chain Triglycerides) diet is a special diet which is sometimes required by children for a short period of time in hospital after heart or chest surgery or for a short period of time at home. It allows a special type of fat which is not absorbed into the lymph system. If your child requires this diet, the medical staff at your child’s hospital will advise you of the requirement, and the dietitian will help you to understand how to follow the diet at home, and when the diet is finished how to go back to your child’s usual diet. The dietitian will also provide recipes and food supplements as required.  For more information and recipe ideas see LHM’s MCT Diet booklet.

This booklet is designed to be used in conjunction with the information and recipes from your dietitian, and aims to provide further recipe ideas, useful food ideas, and to support families at what can be a difficult time by providing practical information.

Please do not follow this diet unless you have been instructed to do so by your child’s cardiology team.

The MCT diet is prescribed when a child or young person is experiencing problems with a build up of fluid within their chest or abdomen.

Everyone has a collection of lymph vessels, similar in look to blood vessels, that carry fat (lymph) around the body. During cardiac surgery, a lymph vessel may get damaged which will cause its contents (lymph fluid) to leak into a chest space. Lymph fluid may also seep from the lymph system into the chest or abdomen due to differences in pressure within the circulation especially after surgery like the Fontan. The collection of lymph fluid in the chest is called a chylothorax.

To help reduce this fluid and allow the lymph vessels to heal, a diet that includes a reduction in fat intake, the MCT diet, will be prescribed. Your child’s medical team may also prescribe a low fluid intake. It sounds quite daunting and does require some extra effort, but it is only for a fairly short period of time. Your child’s dietitian will be able to help you with any concerns you have, and other parents (who you can contact via Little Hearts Matter) may have ideas which worked for their child which could help you. Babies may also be prescribed this diet.

Foods allowed freely on the MCT diet need to have less than 0.2g fat per serving (not per 100g). In general terms, this includes most fruit and vegetables, skimmed milk products, water or fruit juice based drinks, and some foods you have made yourself using MCT oil which is a safe fat.

Your dietitian will send you home with a supply of MCT oil, Liquigen and any calorie supplements or other prescription items you need.

Be very careful when you are reading the labels, as there are lots of different labelling systems, some of which are quite confusing. Some foods are described as ‘low fat’ but are definitely not suitable for this diet. Others (especially diet products) may draw attention to a relatively low amount of saturated fat, but the total fat content may still be too high. Percentages of fat are sometimes quoted, which could be confusing – just ignore percentages.

There is also lots of publicity about ‘good’ fats e.g. Omega 3 fats found in fish such as salmon or in nuts or trans-fats – remember that these are still unlikely to be suitable for an MCT diet – the only ‘good’ fat for this diet is where you have cooked something yourself using MCT oil or Liquigen. (You will be given an initial supply of these products when you leave hospital, and will be given help with ordering further supplies as needed).

In addition, your child will be allowed a set number of daily portions of food which include 1g of fat. This may be referred to as a system of exchanges.

For example, a four-year-old would typically be allowed three exchanges or three grammes of fat per day. These are usually either the protein part of the meal (e.g. a 30 g portion of skinless chicken breast, a 100g portion of plain white fish such as cod) or a treat from a special list of permitted treats (e.g. a Jaffa Cake).

Because they are so high in fat, many foods will have to be excluded completely from the child’s diet for this time, in particular many types of meat (unless given in extremely small portions and counted as an exchange), sausages, normal cheese, nuts, egg yolk or foods containing whole eggs, potato products such as oven chips or waffles, chocolate, most biscuits and cake.

Although this may all seem very daunting, with some imagination, careful shopping and patience in the kitchen, it is possible to create alternatives to many of your child’s favourite foods. For example, they could have a hot chocolate drink made with skimmed milk and chocolate flavouring (liquid flavouring or essence found in the baking section of the supermarket) with marshmallows on top. You might find it helpful to involve your child with the shopping and cooking. Another practical tip is to cook in bulk and freeze portions of food.

Try not to worry about your child’s weight whilst they are on the MCT diet. Although your child will be on a low fat diet, your dietitian will advise about food fortification and use of suitable nutritional supplements to ensure sufficient calorie provision to support weight maintenance and growth during this period.

It may be easier if your child does not eat out or eat at other people’s houses for the duration of the diet unless you are able to take pre-prepared food with you. It will be much safer to provide your child’s meal knowing that it is right for them.

Babies and the MCT diet

Babies may sometimes have to follow the MCT diet. As with children, you must not follow this diet unless it has been prescribed by your child’s cardiologist.

Feeding babies with heart conditions can be challenging, so please contact LHM if you would like any support or guidance if your baby is on the MCT diet.

Sadly breast milk would not be allowed on this diet because its fat content is too high. It is possible to continue to express during the diet so breast feeding can continue after the diet has finished. A special MCT milk will be made up by the dietitians at the hospital, and you will be given instructions on how to make this at home. If you struggle to get your child to accept the new milk, as it may taste different to their usual formula or breast milk, then consult with your dietitian for advice.

As babies with heart conditions have increased energy requirements and may be on high calorie milks and weaning diets prior to starting the MCT diet, the dietitian may ask the GP to prescribe a liquid MCT fat supplement to fortify the MCT milk and low fat purées in order to increase calorie content and promote weight gain. Check the fat content of any bought baby foods very carefully, as even simple foods such as baby rice may have added milk powder, which would make them unsuitable for the MCT diet. As with all of this diet, you need to check that bought foods would be less than 0.2g fat per serving. If you are in a position to make your own baby foods make plain fruit and vegetable purées which can be fortified with your baby’s special MCT milk, Liquigen, or the butter substitute (recipe page 10 of the booklet).

For ideas of recipes download the LHM MCT diet booklet.

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Modified Norwood Procedure (Stage One)




This is normally performed within a few days of birth or diagnosis of Hypoplastic Left Heart Syndrome, while the ductus arteriosus (connection which joins the lung artery and the body artery) is being kept open with Prostaglandin therapy. (See Fetal Circulation).

The aims of the first operation are:

  • To improve the flow of red blood (oxygenated blood) around the body by attaching the base (trunk) of the lung artery (pulmonary artery) to the body artery (aorta). It may be necessary to enlarge the body artery with a patch.
  • To provide a blood flow to the lungs through a passage (shunt), creating a link between the lung artery (pulmonary artery) and the body artery (aorta). The passage is made out of soft plastic (Gore-Tex).
  • To create a permanent passage (septectomy) between the collecting chambers (left and right atrium) ensuring that a mix of red (oxygenated) blood and blue (deoxygenated) blood is flowing around the body.

This operation is extremely complicated and holds a high risk (chance of the baby dying). Ask your surgeon about the risk for your child. The baby may need to be in hospital for some weeks following this surgery to ensure that their condition is stable before being sent home.

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Modified Norwood Procedure (Norwood with a Sano Shunt)



The reconstruction of the main artery leaving the right side of the heart (pulmonary / aorta vessel) remains as described above; this provides a flow of blood to the body.

The lung (pulmonary) flow of blood is provided by a Gore-Tex tube that leads from the right pumping chamber (right ventricle) to the left lung vessel (pulmonary artery). This connection ensures that blood reaches the lungs where it collects oxygen that is then passed around the body.

This, like the previously described procedure, is an extremely complicated operation and holds a high risk (chance of the baby dying). Ask your surgeon about the risks for your child.

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Possible complications

This section explores the sort of complications that can occur before, during or after heart surgery when a child or young adult has a single ventricle heart.

When doctors discuss a new baby’s diagnosis and the treatment path that they plan for them to travel, they also discuss the risks that go hand in hand with a complex heart problem and the treatments available.

Most parents understand that there are major problems when you only have one heart pump.

Here we briefly discuss a broad range of problems that can occur. It is very important that parents, and patients themselves as they get older, talk to their medical team about the risks as not all problems are a risk for each child.

Low oxygen levels

All children with a cyanotic heart condition (blue children) have lower-than-normal oxygen levels. It is safe for them to be moderately low for short periods of time, especially when there is a treatment plan in place and the children are carefully monitored, but if left too low for long periods of time it can affect energy levels and brain function.

There is also a risk of low oxygen levels when a child undergoes surgery or in the post-operative recovery time, especially if the team use the heart-lung bypass machine. Low oxygen levels leading to problems with the brain are known as neurological incidents.

Doctors will explain the risk of low oxygen levels but they will also work to reduce that risk as much as they can.


All children get coughs and colds which need treating in the normal way but post-operatively there is a risk that the chest scar wound both inside the body and on the skin will become infected. The doctors work to prevent this by giving antibiotics but it can still occur after surgery. If the scar is weeping or red a test will be done to identify the type of infection and treatment will begin.

There is also a risk of something called bacterial endocarditis. This is an infection that starts in the mouth and can travel to the heart. For more information about dental care and endocarditis see Dental Care section.

Blood loss

After any operation there is a risk of bleeding. Blood loss will be measured and replacements will be given if the medical staff feel that the loss is compromising blood flow. If the blood pressure remains low for long periods the kidneys are unable to work properly and ultimately blood containing oxygen is unable to reach the brain.

If bleeding occurs between the heart muscle and the outside skin of the heart it can cause problems with the pumping of the heart. If this happens the surgeons may need to remove the blood that has collected there.

Chest drain losses

After chest surgery children and adults have chest drains inserted to ensure that any fluid or blood in the chest can drain away. In some cases the drainage becomes excessive. This could be increased blood loss or because fluid fat is leaking in the chest. If the drainage is excessive, and doctors are unable to keep fluid intake in balance, children can go into shock and collapse.


The heart is responsible for pumping blood around the body. If the heart is not working efficiently, especially around the time of surgery, there is a risk that the blood will clot on areas where surgery has been performed or in pockets of the heart where blood moves slowly. There are also changes to the liver’s function in patients who have a Fontan circulation which makes the risk of clotting greater than normal. There are a number of risks associated with this clotting. The heart’s pumping can be compromised if clots grow within the heart. Small bits of the clot can travel into the lungs, causing problems with breathing, or to the brain where they could cause a stroke. Children and young adults undergoing heart surgery or living with a Fontan circulation are often prescribed anticoagulation medication to reduce the risk of clots. See LHM’s booklet Living with Anticoagulation.


A stroke is a disruption to the circulation of blood to the brain either because of a bleed or because of a blockage, usually a clot. This disruption causes damage to the brain tissue, a condition that is called a stroke. Strokes can take different forms. They can affect mobility, sight, speech and memory, and can cause developmental problems. Medical teams will be working to avoid strokes by making sure that the risk of clots is low, and that the heart is supported to pump well and maintain the oxygen circulating to the brain.


An arrhythmia is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slowly, or with an irregular rhythm. Children with single ventricle hearts have a risk of arrhythmias because of the structure of their heart. The risk is increased after surgery when the circulation has been altered. Arrhythmias can be treated with medications or the use of a pacemaker but often a post-operative arrhythmia will disappear once the heart has recovered from the operation.

A number of these complications can occur routinely around the time of surgery or treatment and so the medical and nursing staff will be watching for them and will intervene with treatment swiftly to help resolve the problems.

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Preparation for hospital

Many families contact Little Hearts Matter for advice about how to prepare their children for the later stages of surgery or for a hospital admission for a cardiac catheter. For more information about this see section on Preparation for hospital.

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Surgical treatments for right-sided single ventricle conditions

It is often difficult to predict which early procedure will be most helpful in supporting a newborn baby with a complex right-sided single ventricle condition. Some children are born with too much blood flowing to their lungs, others with not enough. In some conditions it is not until after birth that the doctors are able to decide exactly which of the following procedures will be needed by each child.





Many single ventricle conditions cause a restriction of the blood supply to the lungs. As it is essential that blood flows to the lungs to collect oxygen for the body, connections must be created to re-route blood around any blockages within the heart. Surgeons will insert tubes made of either donated heart tissue or Gore-Tex (a specialised plastic) to form connections from the body circulation to the lung circulation. This treatment is often used within the first few weeks of life, as it is a simple solution to the circulation problem. Further more complex surgery will be done as the child grows.





Some children are born with a circulation that causes too much blood flow to the lungs. If the lungs are left with too high a flow, this can damage the lung blood vessels over time. To prevent this damage a band is placed around the base of the lung artery (pulmonary artery). This is usually removed at a later stage of surgery.

Septostomy or Septectomy




Many of the children are born with valves that are malformed so that they block the flow of blood around the heart. It is important to divert blood around the blockages by creating extra channels within the heart. Doctors may choose to create a hole between the two collecting chambers (atria) of the heart either during a cardiac catheterisation or during surgery.

Septectomy is the surgical procedure.

Septostomy is a cardiac catheterisation procedure. (See Cardiac Tests).

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We are working on this and hope to have it updated for you as soon as possible. The office team may be able to chat through some issues so do feel free to ring us on 0121 455 8982.


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