Ventricular Septal Defect
What is VSDVentricular septal defects can be categorized according to their size, location, number and the presence or not of aneurysm.
Ventricular septal defects can be small (or restrictive), moderate or large ( non restrictive). Ventricular defects located in the lower portion of the septum are called muscular ventricular septal defects, those in the membranous septum are called perimembranous or membranous. If the defect is close to where the blood enters the ventricle chambers it is called inlet VSD and if it is located close to where the blood exits the ventricle chambers it is called outlet VSD.
If an aneurysm (thin flap of tissue) is present, the chances of a spontaneous closure are increased.
In the Normal Heart
In the normal heart, the blood returns from the lungs to the left ventricle to be distributed to the body. In children with Ventricular septal defects, the blood in the left ventricle flows to the right ventricle through the hole instead of being pumped to the aorta. The heart has to work harder to pump more blood.
What does a VSD do?
The wall between ventricles is meant to separate blood passing through each. This is to prevent mixing of "impure" blood from the veins with "pure" blood going to t e arteries.
When the wall is "broken", mixing occurs. Fortunately, though, only "pure" blood flows from the left ventricle into the right; no flow is seen from the right ventricle across the VSD and so "impure" venous blood does not reach the arteries. This is because pressure in the left ventricle is much higher than the right, and fluids always flow from places of high to lower pressure.
Because of this flow from left to right ventricle across the VSD - also called a LEFT to RIGHT SHUNT - more blood than normal flows into the lungs. Just as in atrial septal defects (ASD), this causes frequent "chest colds" and breathing difficulty in children. When the VSD is large, in a very small child, lung blood flow may be so enormous that the tiny ventricles cannot pump such a volume. This causes HEART FAILURE. Heart failure in a child produces rapid shallow breathing, excessive sweating, inability to feed well, irritability, constant crying, and a failure to grow normally.
Have you felt a kitten purring ? Well, here's something interesting about these children with VSD. When you place your hand over their chest, there is a sensation just like that - called a THRILL. It is produced by the forceful flow of blood across the VSD !
One effect seen in VSD - but not in ASD - is the rapid development of changes in the blood vessels of the lungs. These arteries and veins become thick walled and hard early in life. The reason for this is perhaps because blood from the left ventricle, which is the most powerful chamber of the heart, is pumped under high pressure across the VSD into the lungs. To withstand such force, the tubes carrying blood become thick and strong.
How does it affect the Child?
The symptoms depend on the size of the defect. If the defect is small, it generally closes spontaneously and has no associated symptoms. However there can be a risk for endocarditis, a bacterial infection of the heart caused by a bacteria after any dental or medical operation. In these cases antibiotics should be administered. If the defect is small, it generally closes spontaneously and has no symptoms associated. However, if the defect is moderate or large, spontaneous closures are rare. In this case, the extra blood flow to the lungs will increase the pressure in the left side of the heart, thus forming a difference between the left and the right sides of the heart. The blood will go where there is less resistance, to the right ventricle instead of flowing to the body. This will lead to pulmonary overcirculation resulting in an increased pulmonary artery pressure and congestive heart failure when the heart will not be able to provide the extra workload. At that stage, the child will encounter the following symptoms: Quick fatigue, poor feeding, slow growth rate, rapid breathing and pale appearance.
Symptoms can also be seen according to the location. Muscular VSDs generally closes spontaneously. Membranous VSDs close only if an aneurysm is present.
The child can play and exercise normally. If the defect is small or repaired, he can participate in competitive activities.
VSD along with other defects
VSD may be found alone, as the only defect in a heart that is otherwise normal. Or it may form a part of a "complex" of abnormalities. In this case, it may produce different effects. Some examples of such diseases are TETRALOGY of FALLOT, TRANSPOSITION of the GREAT VESSELS and DOUBLE OUTLET RIGHT VENTRICLE. To avoid confusion, I will describe these conditions separately in other articles.
Can it be fixed?
Most defects, especially the small ones, do not need fixing. Large defects can be fixed. When the child is diagnosed after having developed symptoms of congestive heart failure, medicines should be given prior to surgery. These medications will include digoxin as a diuretic to reduce to extra workload and increase the strength of the heart. If the medications are not enough, then a surgical operation must be considered. During the open heart surgery, a prosthetic patch is placed to cover the defect. Surgery is usually successful and the risk for complications like heart block or incomplete closure is very low.
What happens if VSD is left untreated?
The changes I have just described keep progressing. Soon the heart fails to keep up with the high blood flow, and heart failure sets in. When the lung blood vessels become very thick, the problem of PULMONARY HYPERTENSION arises. This is a situation where the lung arteries are severely damaged, and at this stage, even surgical repair of the VSD will not be able to cure the disease. When the VSD is located in the upper part of the inter-ventricular wall, close to the aortic valve, it can slowly make the aortic valve "leaky" - a condition called AORTIC REGURGITATION. This usually takes many years. In small VSD's, none of these things are seen often. But there is one complication peculiar to a small VSD - INFECTIVE ENDOCARDITIS. Due to a jet of blood across the VSD, the inner lining of the heart gets damaged. Bacteria can infect this injured layer easily.
Truncus Arteriosus (or Common Arterial Trunk)
The aim of this fact sheet is to explain what Truncus Arteriosus is, what effect it will have on a child and how it can be treated.
What is Truncus Arteriosus?
When a baby’s heart is developing in the womb, one large blood vessel, the truncus arteriosus, should divide to become the two main arteries: the aorta, and the pulmonary artery.
The aorta carries red (oxygenated) blood from the heart to the body, and the pulmonary artery carries blue (deoxygenated) blood to the lungs.
If the aorta and pulmonary artery do not divide, the child is born with a persistent truncus arteriosus or common arterial trunk. This one big artery has one large valve instead of there being two arteries with pulmonary and aortic valves.
The aorta carries red (oxygenated) blood from the heart to the body, and the pulmonary artery carries blue (deoxygenated) blood to the lungs.
If the aorta and pulmonary artery do not divide, the child is born with a persistent truncus arteriosus or common arterial trunk. This one big artery has one large valve instead of there being two arteries with pulmonary and aortic valves.
A part of the wall between the left and right ventricles is missing (Ventricular Septal Defect). This means that the truncus arteriosus is able to receive blue blood from the right side of the heart, and red blood from the left side of the heart.
The truncus arteriosus divides into the aorta and the pulmonary arteries, which carry this mixture of blood to the lungs and to the body. There are 4 possible types:
The truncus arteriosus divides into the aorta and the pulmonary arteries, which carry this mixture of blood to the lungs and to the body. There are 4 possible types:
- Type 1 - the pulmonary artery branches off just above the valve.
- Type 2 - the pulmonary arteries to the lungs branch separately but close together directly off the truncus.
- Type 3 - the pulmonary arteries branch separately and are further apart.
- Type 4 - common arterial trunk with pulmonary atresia, often known as pseudotruncus
There may be other differences that affect how your child is treated – e.g. the VSD may be missing or the valve may not work well.
The result of truncus arteriosus is usually that too much blood is going to the lungs and too little red (oxygenated) blood is reaching the body.
The result of truncus arteriosus is usually that too much blood is going to the lungs and too little red (oxygenated) blood is reaching the body.
Diagnosis
Truncus Arteriosus can sometimes be seen on a scan during pregnancy.
After birth your baby may have been diagnosed because a heart murmur was heard. The child becomes increasingly blue (cyanosed), because of the blue blood going being pumped to the body instead of the lungs.
Because of the high pressure they will develop congestive heart failure as blood flow to the lungs increases, be breathless, difficult to feed and ‘fail to thrive’.
When a heart defect is suspected the tests used can be:
After birth your baby may have been diagnosed because a heart murmur was heard. The child becomes increasingly blue (cyanosed), because of the blue blood going being pumped to the body instead of the lungs.
Because of the high pressure they will develop congestive heart failure as blood flow to the lungs increases, be breathless, difficult to feed and ‘fail to thrive’.
When a heart defect is suspected the tests used can be:
- Pulse, blood pressure, temperature, and number of breaths a baby takes a minute;
- Listening with a stethoscope for changes in the heart sounds;
- An oxygen saturation monitor to see how much oxygen is getting into the blood;
- A chest x-ray to see the size and position of the heart;
- An ECG (electrocardiogram) to check the electrical activity;
- An ultrasound scan (echocardiogram) to see how the blood moves through the heart;
- Checks for chemical balance in blood and urine; and
- A catheter or Magnetic resonance Imaging test may be needed.
Treatment
The aim of the treatment is to separate the circulation of the blood so that blue blood goes to the lungs, and red to the body.
Surgery
Surgery will be needed before the increased pressure damages the lungs (pulmonary vascular disease). This will be open heart surgery. The heart will need to be stopped and opened to repair it. This means that a machine will have to take over the job that the heart and lungs normally do – the heart bypass machine.
Surgery may involve placing a donor lung artery from the right ventricle to the branch lung arteries, and a plastic patch is usually used to close the hole (VSD). There is no risk of rejecting the donor lung artery, since it is not living blood vessel.
The truncus will now act as the aorta, carrying red blood from the left ventricle to the body. Surgeries will need to be repeated as your child grows.
The more complicated types of truncus arteriosus may be treated with a Fontan operation.
Surgery may involve placing a donor lung artery from the right ventricle to the branch lung arteries, and a plastic patch is usually used to close the hole (VSD). There is no risk of rejecting the donor lung artery, since it is not living blood vessel.
The truncus will now act as the aorta, carrying red blood from the left ventricle to the body. Surgeries will need to be repeated as your child grows.
The more complicated types of truncus arteriosus may be treated with a Fontan operation.
How the child is affected
Most babies are well, active, and gaining weight a few days after surgery. They will have a scar down the middle of the chest, and there may be small scars where drain tubes were used. These fade very rapidly in most children, but they will not go altogether. Smaller scars on the hands and neck usually fade away to nothing.
It is not uncommon for a child to pick up an infection, such as a chest infection or infected wound, while undergoing treatment.
After the surgery, your child will be monitored regularly by a cardiologist. Some of these problems can occur after surgery or later in life:
It is not uncommon for a child to pick up an infection, such as a chest infection or infected wound, while undergoing treatment.
After the surgery, your child will be monitored regularly by a cardiologist. Some of these problems can occur after surgery or later in life:
- The truncal valve may need replacement with an artificial valve. If this happens the child will need to take an anticoagulant medicine to stop blood clots forming. The anticoagulant effect has to be monitored frequently using a blood test – see Warfarin fact sheet.
- Because the flow of blood is slower than it should be in the conduit, there may be a danger of blood clotting – if this is thought to be a problem in your child’s case, your child may need to take anticoagulants (aspirin or warfarin).
- The electrical system of the heart is sometimes damaged, causing a very fast heart beat – a Supraventricular Tachycardia, or SVT – to occur. This may be improved with medicine or ablation.
Unfortunately, because the conduit that has been put in doesn’t grow with the child, further surgery will be needed as he or she gets bigger.
