Ventricular Septal Defect

What Is Ventricular Septal Defect?

Ventricular (ven-TRICK-u-lar) septal defect (VSD) is a hole (defect) in the wall that separates the lower chambers of the heart. The lower chambers of the heart are called the ventricles (VEN-trih-kuls). The wall between them is called the ventricular septum. In the normal heart, the septum prevents blood from flowing directly from one ventricle to the other. In a heart with a VSD, blood can flow directly between the two ventricles.

The How the Heart Works section in this article explains the normal heart and blood flow in detail.

VSD is a congenital heart defect, which means that it is present at birth. In children with a VSD, blood usually flows through the defect from the left ventricle to the right ventricle. This causes extra blood (called volume overload) in the pulmonary (PULL-mun-ary) arteries and lungs, and in the left atrium and left ventricle.

Heart Cross Section with Ventricular Septal Defect (VSD)

Figure A shows the normal anatomy and blood flow of the interior of the heart. Figure B shows two common locations of ventricular septal defects. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle.

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.

Characteristics of VSD

VSD is the most common type of congenital heart defect. Infants born with a VSD may have a single hole or more than one hole in the wall that separates the two ventricles. The defect may also occur by itself or with other congenital heart defects.

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:
- Do not cause symptoms in infants and children
- Close on their own, often by school age
- 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.

Outlook

Most VSDs close on their own or are so small that they don't need treatment. Some children and adults need surgery or other procedures to close the VSD, especially if it is large. Most children and adults live long and productive lives after their VSD closes or is repaired.

How the Heart Works

Your child's heart is a muscle about the size of his or her fist. The heart works like a pump and beats about 100,000 times a day.

The heart has two sides, separated by an inner wall called the septum. The right side of the heart pumps blood to the lungs to pick up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of the heart, and the left side pumps it to the body.

The heart has four chambers and four valves, and it is connected to various blood vessels. Veins are the blood vessels that carry blood from the body to the heart, while arteries are the vessels that carry blood away from the heart to the body.

Illustration: Healthy Heart Cross-Section

Heart Chambers

The heart has four chambers or "rooms"—two on the left side of the heart and two on the right.

The atria (AY-tree-uh) are the two upper chambers that collect blood as it comes into the heart.
The ventricles are the two lower chambers that pump blood out of the heart to the lungs or other parts of the body.

Heart Valves

Four valves control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart.

The four valves are:

The tricuspid (tri-CUSS-pid) valve in the right side of the heart, between the right atrium and the right ventricle
The pulmonary valve in the right side of the heart, between the right ventricle and the entrance to the pulmonary artery that carries blood to the lungs
The mitral (MI-trul) valve in the left side of the heart, between the left atrium and the left ventricle
The aortic (ay-OR-tik) valve in the left side of the heart, between the left ventricle and the entrance to the aorta, the artery that carries blood to the body

Valves are like doors that open and close. They open to allow blood to flow through to the next chamber or to one of the arteries, and then they shut to keep blood from flowing backwards.

When your heart's valves open and close, they make the familiar "lub-DUB" or "lub-DUPP" sounds that your doctor can hear using a stethoscope.

The first sound is made by the tricuspid and mitral valves closing at the beginning of systole (SIS-toe-lee). Systole is when the heart contracts, or squeezes, and pumps blood out of the heart.
The second sound is made by the aortic and pulmonary valves closing at the beginning of diastole (di-AS-toe-lee). Diastole is when the heart relaxes and fills with blood.

Arteries

The arteries are the major blood vessels connected to your heart.

The pulmonary artery carries blood pumped from the right side of the heart to the lungs to pick up a fresh supply of oxygen.
The aorta is the main artery that carries oxygen-rich blood pumped from the left side of the heart out to the body.
The coronary arteries are the other important arteries attached to the heart. They carry oxygen-rich blood to the heart muscle, which must have its own blood supply to function.

Veins

The veins are major blood vessels connected to your heart.

The pulmonary veins carry oxygen-rich blood from the lungs to the left side of the heart so it can be pumped out to the body.
The vena cava are two large veins that carry oxygen-poor blood from the body back to the heart.

What Causes Ventricular Septal Defect?

Doctors do not know what causes ventricular septal defect (VSD).

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.

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 checkup. 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
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

An echocardiogram, which is harmless and painless, uses sound waves to create a moving picture of your baby's heart. During an echocardiogram, reflected sound waves outline the heart's structure completely. The test allows the doctor to clearly see any problem with the way the heart is formed or the way it's working. An echocardiogram is the most important test available to your baby's cardiologist to both diagnose a heart problem and follow the problem over time. With VSD, the echocardiogram shows exactly where the hole is located in the wall between the two lower heart chambers, how big the hole is, and whether the heart is overworking because of the defect. An echocardiogram also is used for a baby with VSD to make sure there are no other problems with the heart's structure.

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 (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 catheterization. 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 catheterization is rarely used for diagnosis unless the echocardiogram does not provide enough information or if other defects or problems are suspected.

How Is 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

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

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
Digoxin to improve heart function and keep the heartbeat regular

Antibiotics to prevent bacterial endocarditis are usually given for a limited time after surgery or a catheter procedure.

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.

The surgical procedure. The surgery to close a VSD is done under general anesthesia 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.

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.
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 pediatrician 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.

Last Updated : June 2007

Sources and References

This article is in Public Domain. It is reprinted and modified from NIH.

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