Ventricular Septal Defect

Ventricular Septal Defect

1. What is VSD (Ventricular Septal Defect)?

VSD (Ventricular Septal Defect), is a condition where a defect is present in the ventricular septum (also called the interventricular septum) – the muscular wall of the heart between the two ventricles (left and right). The defect manifests as a “hole” within this wall.

In the illustration above, the ventricular septum is indicated by the red rectangle.

VSD is one of a group of heart problems found in newborn babies that are collectively called congenital heart disease, of which it is the most commonly occurring. Congenital heart diseases, which are also called congenital heart defects, are characterized by a variety of malformations of the heart or blood vessels which are present at birth. They occur when the heart or blood vessels do not develop properly before birth.

Ventricular septal defect accounts for about 15% of all cases of congenital heart disease in the United States.

Types of VSD

Doctors classify VSDs based on the:

· Size of the defect.

· Location of the defect.

· Number of defects.

· Presence or absence of a ventricular septal aneurysm—a thin flap of tissue on the septum. It is harmless and can help a VSD close on its own.

VSDs range in size from small to large

· Small VSDs usually allow only a small amount of blood flow between the ventricles. Because of this, they are sometimes called restrictive. Most small VSDs:

o Do not cause symptoms in infants and children

o Close on their own, often by school age

o Rarely need surgery or other procedures to close the defect

· Moderate (or medium-sized) VSDs are less likely than small defects to close on their own. They may require surgery to close and may cause symptoms during infancy and childhood.

· Large VSDs allow a large amount of blood to flow from the left ventricle to the right ventricle and are sometimes called nonrestrictive. A large VSD is less likely to close completely on its own, but it may get smaller. A large VSD can cause more symptoms in infants and children, and surgery is usually needed to close it.

VSDs are found in different parts of the septum

· Membranous VSDs are located near the heart valves. They can close at any time if a ventricular septal aneurysm is present.

· Muscular VSDs are found in the lower part of the septum. They are surrounded by muscle, and most close on their own during early childhood.

· Inlet VSDs are located close to where blood enters the heart. They are less common than membranous and muscular VSDs.

· Outlet VSDs are found in the part of the ventricle where the blood leaves the heart. This is the rarest type of VSD.

Effects of VSD

Over time, a VSD that does not close—especially a large VSD—can cause:

· Congestive heart failure

Infants with large VSDs may develop congestive heart failure. Extra blood flows from the left ventricle through the right ventricle to the lungs and back to the left atrium and on to the left ventricle. This causes the left atrium and left ventricle to handle an increased amount of blood, and the workload on the heart increases. The increased workload on the heart also increases the heart rate and the body's demand for energy. The extra blood flow in the lungs may cause rapid breathing, while also increasing the body's demand for energy.

· Growth failure, especially in infancy

Your baby may not be able to eat enough to keep up with his or her body's increased energy demands. Your baby may lose weight or fail to grow and develop as he or she should.

· Bacterial endocarditis is an infection of the lining of the heart, valves, or arteries

Endocarditis often occurs following dental and medical procedures.

· Irregular heartbeat or rhythm (arrhythmia)

The extra blood flowing into the left atrium can cause the atrium to stretch and enlarge. When this occurs, your child can develop a fast heartbeat with symptoms such as dizziness or fainting.

· Pulmonary artery hypertension (high blood pressure in the pulmonary arteries)

If a moderate or large VSD is not closed, sustained blood flow under higher pressure into the pulmonary arteries causes the arteries to become thickened and stiff. The amount of blood flow to the lungs decreases over time as the resistance to blood flow into the pulmonary arteries increases. However, this causes the right ventricle to work harder. Today, pulmonary artery hypertension rarely develops because most large or moderate VSDs are closed in infancy or early childhood.

In a normal heart, the right ventricle pumps blood to the lungs and the left ventricle pumps blood throughout the body. In VSD, the presence of a hole between the two ventricles causes a backflow of blood from the left ventricle (which contains oxygenated blood from the lungs) into the right ventricle (which pumps deoxygenated blood from the body to the lungs). This means that some of the oxygenated blood recycles through the lungs AGAIN, before returning to the left ventricle. This results in less oxygenated blood reaching the body, and makes the heart work more since there is less oxygenated blood to circulate. This means that as compared to a normal functioning heart, a heart with VSD is less efficient.

It must also be noted that the two ventricles, left and right, have different systolic pressure (the blood pressure (as measured by a sphygmomanometer) during the contraction of the left ventricle of the heart). The left ventricle has a systolic pressure of ~120 mm Hg while the right ventricle has systolic pressure of ~20 mm Hg. With the leakage of blood into the right ventricle from the left ventricle, this therefore elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms. This effect is more noticeable in patients with larger defects. Patients with smaller defects may be asymptomatic.

Over time, increased backflow of blood may cause the right ventricle to enlarge (as a way to cope with the abnormally high pressure it must withstand due to the backflow). This may lead to other problems, such as abnormal heartbeats and increased blood pressure to the lungs. These problems may make it difficult for the heart and lungs to supply oxygen to the body.

If the hole is sufficiently large, the lack of oxygen being delivered to the body can cause severe problems, including heart failure and breathlessness, and also poor feeding and failure to thrive in infancy.

Approximately 0.7% of all babies have a congenital heart defect. Of these, 20%-30% have a ventricular septal defect or about 2-3 per 10000 births.

2. What causes a VSD (ventricular septal defect)?

It is not exactly known what causes a VSD.

Doctors think that problems during the development of your child's heart may cause VSD. The following are possible factors or conditions which may increase your child's risk of having a VSD:

Ø Certain medicines, illegal drugs, or alcohol used early in your pregnancy.

Ø Family history of a VSD or other heart problems

Heredity may play a role. Parents who have congenital heart defects are more likely to have a child with VSD than parents who do not have congenital heart defects. In some cases, VSD may be due to a defect in one or more genes or to chromosomal abnormalities.

Ø If your child has other congenital conditions, such as Down syndrome

Problems with the information in genes are also thought to cause a VSD. A gene is a little piece of information that tells your body what to do or what to make.

Ø Uncontrolled diabetes (high blood sugar) during pregnancy

3. What Are the Signs and Symptoms of Ventricular Septal Defect?

The major signs and symptoms of ventricular septal defect (VSD) are:

· Heart murmur

· The signs and symptoms of congestive heart failure

· Slowed growth

Most newborns with VSD do not have heart-related symptoms.

Heart Murmur

A heart murmur is an extra or unusual sound heard during your heartbeat. It is usually present in VSD and may be the first and only sign found by your doctor. The heart murmur is often present right after birth in many infants, but it may not appear until the baby is 6 to 8 weeks old. Sometimes the heart murmur is not found until the child is older or much later in life as an adult.

Congestive Heart Failure

A baby with a moderate or large VSD can develop congestive heart failure. These symptoms usually appear during the baby's first 2 months of life. Some older children and adults with VSD also may develop symptoms of congestive heart failure, which include:

· Fatigue or tiring easily

· Shortness of breath

· Fast breathing

· Slow growth and poor weight gain

How Is Ventricular Septal Defect Diagnosed?

Ventricular septal defect (VSD) is diagnosed using a medical history, a physical exam, and tests. Your baby's doctor may see symptoms of VSD during a routine check-up. Some parents also notice signs, such as poor feeding, and bring the baby to the doctor.

Most cases are diagnosed in infancy and childhood. Babies born with a large VSD may have symptoms of congestive heart failure by the time they are 1–2 months old. They are usually diagnosed at that time. Some cases are not diagnosed until adulthood.

Medical and Family History

Your child's doctor will ask you about:

· Family history of congenital heart defects

· Your child's symptoms

· Your child's feeding and growth

Physical Exam

During the physical exam, the doctor:

· Listens to your baby's heart with a stethoscope to hear and evaluate a heart murmur (ascultation)

· Looks for signs of congestive heart failure

Tests

Your baby's doctor will order several tests to diagnose VSD. These tests will also help the doctor determine the type and size of the defect.

Echocardiogram (ultrasound)

An echocardiogram or ultrasound study of the heart is the test used most often to diagnose VSD. This test uses sound waves to create a picture of the heart. An echocardiogram shows movement of blood through the heart and problems with how the heart is formed. It is safe and painless.

An echocardiogram shows:

· VSD location and size

· How much blood is passing through the VSD

· Enlargement of the left atrium and left ventricle

· Other congenital heart defects

Other tests

· Chest x ray. This test takes a picture of the heart and lungs. It can show if the heart is enlarged or if there is fluid in the lungs.

· EKG or ECG (electrocardiogram). This test measures the rate and regularity of your child's heartbeat. It provides an estimate of enlargement of the heart chambers and shows abnormal heart rhythms (arrhythmia).

· Cardiac catheterisation. A thin, flexible tube (catheter) is passed through a blood vessel (artery or vein) to the heart. With the assistance of x rays, the doctor can see the child's blood vessels and heart. During the procedure, the doctor can measure blood pressure in the heart and arteries connected to the heart, and see how much blood is mixing between the two sides of the heart. Cardiac catheterisation is rarely used for diagnosis unless the echocardiogram does not provide enough information or if other defects or problems are suspected.

4. How is a ventricular septal defect treated?

Goals of Treatment

The goals of ventricular septal defect (VSD) treatment are to:

· Monitor the defect to see if it closes or gets smaller

· Treat the symptoms of congestive heart failure, if present

· Close or repair the VSD if it does not close on its own

Most small VSDs close without treatment. But treatment is needed if your child's VSD:

· Is large

· Is causing your child to have symptoms

· Is moderate and does not close on its own by the time your child is in preschool

· Affects the aortic valve

Treatment is either surgical or conservative. Smaller congenital VSDs often close on their own, as the heart grows, and are thus treated conservatively, with prescription medicines, and supplements. Some small congenital VSDs may not ever require surgery.

Types of Treatment

There are several types of treatment for VSD. They include:

· Monitoring and observation

· Medicines

· Extra nutrition

· Surgery or a procedure using catheters to close the VSD

Your child's doctor will discuss treatment options with you and will consider your family's preferences when making treatment recommendations.

Monitoring and observation

This involves regular checkups to see if the VSD may close on its own. This typically lasts for until the child reaches 2 years of age, where in, if the VSD does not close by itself by then, surgery is considered.

Your baby's doctor may choose to monitor and observe the baby if your child does not have symptoms of congestive heart failure. This means regular checkups and tests to see if the defect closes on it own or gets smaller:

· Weekly for infants with large defects.

· Yearly or even less in older children.

· A VSD diagnosed during infancy usually closes or gets smaller. Even large defects may close.

Medicines

Children with small VSDs and no symptoms may not need any medicines. Children and adults who have moderate or large VSDs and develop symptoms of congestive heart failure may need medicine until the defect can be closed. These medicines include:

Diuretics to treat fluid buildup

This medicine may be given to help the child's body and lungs get rid of extra fluid. This can help him breathe easier. Diuretics however, may make him urinate more often.

Heart medicine

This medicine may be given to make the child's heart beat stronger or more regularly. There are many different kinds of heart medicines. It would be best to consult the physician concerned for any questions as to why that medicine is being prescribed, and its intended effects as well as any side-effects it may have.

*(Digoxin to improve heart function and keep the heartbeat regular)

Antibiotics

These are prescribed so as to prevent bacterial endocarditis are usually given for a limited time after surgery or a catheter procedure.

It is recommended to check with the child’s doctor if antibiotics can be given when the child is having his teeth cleaned. Antibiotics may also be given if the child has been exposed to someone with certain infections.

Extra nutrition

Some infants with VSDs do not grow and develop or gain weight as they should. These infants usually include those who:

· Have large VSDs

· Are born prematurely

· Tire easily during feeding

Doctors usually recommend extra nutrition or special feedings for these infants. These feedings are high-calorie formulas or breast milk that give the baby extra nourishment. In some cases, tube feeding is needed. Food is given through a small tube that is placed through the nose into the stomach. Tube feeding can add to or take the place of bottle feeding.

Surgery

Today, most doctors recommend surgery to close a large VSD by 1 year of age. Doctors also recommend closing a VSD that does not close on its own by the time a child is in preschool. Surgery may be required earlier if:

• The child fails to gain weight.
• Medicines are required to control the symptoms of congestive heart failure.

Open surgical procedures require a heart-lung machine and are done with a median sternotomy, in which a vertical inline incision is made along the sternum(breastbone), after which the sternum itself is divided, or "cracked". Percutaneous endovascular procedures are less invasive and can be done on a beating heart, but are only suitable for certain patients. This involves a needle catheter getting access to a blood vessel, followed by the introduction of a wire through the lumen(tube) of the needle. It is over this wire that other catheters can be placed into the blood vessel. This technique is known as the modified Seldinger technique.

Repair of most VSDs is complicated by the fact that the conducting system of the heart (the system responsible for the maintenance of the regular beating of the hear) is in the immediate vicinity.

Respiratory support

Oxygen:

The patient may need oxygen to help him breathe easier. He may need a nasal cannula (small tubes placed in the nose) or mask. Many children do not like having these on their face, so instead the doctors may place the mask next to your child's face. Some children are placed in an oxygen tent or plastic hood.

ET tube:

Your child may need an endotracheal (ET) tube to help him breathe. An ET tube is put in your child's mouth or nose, and goes into the trachea (windpipe). It may be connected to a breathing machine called a ventilator. The ET tube will be taken out when your child is breathing better.

The surgical procedure. The surgery to close a VSD is done under general anaesthesia so that your child will be asleep and feel no pain. The surgeon makes a cut down the center of the chest to reach the VSD.

*Transcatheter device closure:

The doctor may suggest that the child have a transcatheter device closure. This is a procedure where a device called a septal occluder is used to close the hole in the ventricular wall.

• The child is placed on a heart/lung bypass machine during surgery.
• The heart is stopped, and the heart/lung machine takes over for the heart, pumping red blood throughout the body.
• The heart/lung machine also brings oxygen-poor blood back to the machine where it picks up oxygen.
• The surgeon uses a special patch or stitches to close the VSD. (plu or patch)
• The surgeon puts the patch over the VSD and sews it into place.
• Once the repair is completed, the heart is restarted.
• The child is taken off the heart/lung bypass machine.
• The surgeon closes the skin incision.

Within 6–8 weeks, heart tissue will grow over the patch so that it will not need to be replaced as the child grows.

After the surgery. After VSD surgery, your child will spend a few days in the intensive care unit or in a regular hospital room. Most children go home about 4 days after the surgery.

While in the hospital, your child will be given medicine to reduce pain or anxiety. The doctors and nurses at the hospital will teach you how to care for your child at home. They will talk to you about:

• Limits on activity for your child while he or she recovers
• Avoiding blows to the chest while the incision heals
• Bathing the child
• Followup appointments with your child's doctors
• How to give your child medicine at home

Results. The outcomes from VSD surgery are excellent. Your child should have little pain or discomfort.

Complications from VSD surgery, such as bleeding and infection, are rare and short term. After full recovery from surgery, most children are able to participate in normal activities. Children who ate poorly before surgery often start to eat better and gain weight, and they are more active.

Living With Ventricular Septal Defect

Children with small ventricular septal defects (VSDs) usually have no problems and do not need long-term treatment or followup. Also, most children and adults who have successful repair or closure of a VSD and have no other congenital heart defects can expect to lead healthy and active lives.

Medical Needs

Sometimes problems and risks remain after surgical closure. They include:

• Irregular heart beat (arrhythmia). Serious and frequent arrhythmias require regular followup. The risk for arrhythmia is greater if surgery is done later in life.
• Residual or remaining VSD. In some cases, the VSD does not fully close. This is usually due to a leak in the patch. These VSDs tend to be small and do not cause problems. They rarely require another operation. Once catheter-based procedures are readily available, they may be used for this condition.
• Bacterial endocarditis. Antibiotic treatment is recommended for 6 months after VSD surgery. Residual VSDs usually require lifelong treatment with antibiotics. The antibiotics are given in a single dose 1 hour before a dental visit or surgical procedure. Antibiotics are used only to prevent infection and not to treat the VSD.
• Enlarged left ventricle. Long-term volume overload may lead to increased stress and enlargement of the left ventricle.

Special Needs for Children

Activity

There should be no special restrictions on your child once he or she is fully recovered from VSD repair. Regular physical activity is usually allowed. Be sure to check with your child's doctor before allowing your child to participate in any sports.

Growth and development

Your paediatrician or family doctor checks your child for growth and development at each routine checkup. Children with moderate or large VSDs may not grow as quickly as other children. These children usually "catch up" after the VSD is closed.

Special Needs for Teenagers

Teenagers with VSDs—even if the VSDs have been closed—should continue to have regular checkups.

Teenagers or young adults rarely need additional surgery once a VSD closes or is repaired. Your heart doctor (cardiologist) will discuss with you and your teenager the need for any additional heart surgeries.

Special Needs for Adults

Over time, some adults—mostly those whose VSD was repaired later in life—may need medicine to help improve heart function or to help stop irregular heartbeats. Your cardiologist decides if you need any medicine. It is important to check with your cardiologist before changing or stopping any medicines.

Just like teenagers, adults whose VSDs are closed or repaired usually do not need additional surgery. Sometimes it is necessary to have a pacemaker or defibrillator to help stop or control irregular heartbeats. The cardiologist will discuss with you the need for any additional surgeries.

Key Points

• Ventricular septal defect (VSD) is a hole in the wall of the heart that separates the lower chambers (ventricles). This defect allows blood to flow from one ventricle to the other.
• In most cases of VSD, blood flows through the defect from the left ventricle to the right ventricle. This causes extra blood (volume overload) in the pulmonary artery (the blood vessel that carries oxygen-poor blood from the right side of the heart to the lungs) and in the lungs, left atrium, and left ventricle.
• Usually a VSD is not found until after a baby is born. Between 4 and 6 out of every 10 VSDs close on their own, often by the time the child is of school age.
• Most VSDs are so small that they don't need treatment. But some children and adults need treatment to close the VSD—especially if it is large. Today, large or moderate VSDs are usually closed in infancy or early childhood.
• Most children and adults live long and productive lives after their VSD closes or is repaired.
• VSDs range in size from small to large. They can occur in different parts of the septum. They also can occur alone or with other congenital heart defects.
• A VSD that does not close—especially a large VSD—can lead to congestive heart failure or other serious health conditions.
• Doctors do not know what causes VSD. Most cases of VSD develop by chance.
• A heart murmur may be the only sign of a VSD. Some cases are not diagnosed until adulthood.
• A baby with a moderate or large VSD can develop congestive heart failure. These signs usually appear by the time the baby is 2 months old.
• An echocardiogram is the test used most often to diagnose VSD.
• Treatments for VSD include monitoring and observation, medicine, extra nutrition, surgery, and procedures using catheters to close the VSD.
• Children whose VSDs close on their own usually do not need special followup beyond an initial period. Children and adults without spontaneous or surgical closure need regular followup.