Download Ventricular Septal Defect

Ventricular Septal Defect
Animation available at: http://www.childrens-heartfed.com/resources__and__info/heart_conditions/ventricular_septal_defect_vsd
Ventricular Septal Defect
What is a ventricular septal defect?
The normal heart has two sides, the left and the right, which are separated by a
muscular wall called the septum. Each side of the heart also has two parts - an upper
chamber called an atrium and a lower chamber called a ventricle.
Ventricular septal defect (VSD), a congenital (present at birth) defect, is an opening
in the ventricular septum, or dividing wall between the two lower chambers of the
heart known as the right and left ventricles.
Normally, oxygen-poor (blue) blood returns to the right atrium from the body,
travels to the right ventricle, then is pumped into the lungs where it receives oxygen.
Oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left
ventricle, then is pumped out to the body through the aorta.
A ventricular septal defect allows oxygen-rich (red) blood to pass from the left
ventricle through the opening in the septum, and then mix with oxygen-poor (blue)
blood in the right ventricle.
What are the different types of Ventricular Septal Defect?
Two basic types of VSD are:


Perimembranous VSD — An opening in the upper section of the ventricular
septum, near the valves, occurs in 75 percent of all VSD cases.
Muscular VSD — An opening in the lower section of the ventricular septum
occurs in up to 20 percent of all VSD cases.
Ventricular septal defects are the most commonly occurring type of congenital heart
defect, occurring in one to three out of every 1,000 live births, and four to seven out
of every 1,000 premature births.
What causes a ventricular septal defect?
The heart is forming during the first eight weeks of fetal development. It begins as a
hollow tube, then partitions develop within the tube that eventually become the
septa (or walls) dividing the right side of the heart from the left. Ventricular septal
defects occur when the partitioning process does not occur completely, leaving an
opening in the ventricular septum.
Some congenital heart defects may have a genetic link, either occurring due to a
defect in a gene, a chromosome abnormality or environmental exposure, causing
heart problems to occur more often in certain families. Most ventricular septal
defects occur sporadically (by chance), with no clear reason for their development.
Why is ventricular septal defect a concern?
If not treated, this heart defect can cause lung disease. When blood passes through
the VSD from the left ventricle to the right ventricle, a larger volume of blood than
normal must be handled by the right side of the heart, causing the right side to
become overworked and enlarged. Extra blood then passes through the pulmonary
2
artery into the lungs, causing higher pressure than normal in the blood vessels in the
lungs, a condition known as pulmonary hypertension.
A small opening in the ventricular septum allows a small amount of blood to pass
through from the left ventricle to the right ventricle. A large opening allows more
blood to pass through and mix with the normal blood flow in the right heart. The
larger the volume of blood that goes to the lungs, the higher the pressure.
The lungs are able to cope with this extra pressure for while, depending on exactly
how high the pressure is. After a while, however, the blood vessels in the lungs
become diseased by the extra pressure. If this combination of lung disease and
damage to the right side of the heart is severe, it could lead to an inability of the
heart to pump effectively, called congestive heart failure.
As pressure builds up in the lungs, the flow of blood from the left ventricle through
the VSD, into the right ventricle, and on to the lungs will diminish. This helps
preserve the function of the lungs, but causes another problem. Blood flow within the
heart goes from areas where the pressure is high to areas where the pressure is low.
If a ventricular septal defect is not repaired and lung disease begins to occur,
pressure in the right side of the heart will eventually exceed pressure in the left. In
this instance, it will be easier for oxygen-poor (blue) blood to flow from the right
ventricle, through the VSD, into the left ventricle and on to the body. When this
happens, the body does not receive enough oxygen in the bloodstream to meet its
needs.
Because blood is pumped at high pressure by the left ventricle through the VSD,
tissue damage may eventually occur in the right ventricle. Bacteria in the
bloodstream can easily infect this injured area, causing a serious illness known as
bacterial endocarditis.
Some ventricular septal defects are found in combination with other heart defects
(such as in transposition of the great arteries).
What are the symptoms of a ventricular septal defect?
The size of the ventricular septal opening will affect the type of symptoms noted, the
severity of symptoms and the age at which they first occur. A VSD permits extra
blood to pass from the left ventricle through to the right side of the heart, and the
right ventricle and lungs become overworked as a result. The larger the opening, the
greater the amount of blood that passes through and overloads the right ventricle
and lungs.
Symptoms often occur in infancy. The following are the most common symptoms of
VSD. Each child may experience symptoms differently. Symptoms may include:







fatigue
sweating
rapid breathing
heavy breathing
congested breathing
disinterest in feeding, or tiring while feeding
poor weight gain
3
The symptoms of VSD may resemble other medical conditions or heart problems.
Always consult your child's physician for a diagnosis.
What are the treatments for ventricular septal defect?
Specific treatment for VSD will be determined by your child's physician based on:





your child's age, overall health and medical history
extent of the disease
your child's tolerance for specific medications, procedures or therapies
how your child's doctor expects the disease may progress
your opinion or preference
Small ventricular septal defects may close spontaneously as your child grows. A
larger VSD usually requires surgical repair. Regardless of the type, once a ventricular
septal defect is diagnosed, your child's cardiologist will evaluate your child
periodically to see whether it is closing on its own. A VSD will be repaired if it has not
closed on its own -- to prevent lung problems that will develop from long-time
exposure to extra blood flow. Treatment may include:



Medical Management — Some children have no symptoms and require no
medication. Most children, however, may need to take medications to help
the heart work better, since the right side is under strain from the extra blood
passing through the VSD. Medications that may be prescribed include the
following:
o Digoxin -- A medication that helps strengthen the heart muscle,
enabling it to pump more efficiently.
o Diuretics -- The body's water balance can be affected when the heart
is not working as well as it could. These medications help the kidneys
remove excess fluid from the body.
Adequate Nutrition — Infants with a larger VSD may become tired when
feeding, and are not able to eat enough to gain weight. Options that can be
used to ensure your baby will have adequate nutrition include the following:
o High-calorie Formula or Breast milk -- Special nutritional supplements
may be added to formula or pumped breast milk that increase the
number of calories in each ounce, thereby allowing your baby to drink
less and still consume enough calories to grow properly.
o Supplemental Tube Feedings -- Feedings given through a small,
flexible tube that passes through the nose, down the esophagus and
into the stomach can either supplement or take the place of bottle
feedings. Infants who can drink part of their bottle, but not all, may be
fed the remainder through the feeding tube. Infants who are too tired
to bottle-feed may receive their formula or breast milk through the
feeding tube alone.
Infection Control — Children with certain heart defects are at risk for
developing an infection of the inner surfaces of the heart known as bacterial
endocarditis. A common procedure that puts your child at risk for this
infection is a routine dental check-up and teeth cleaning. Other procedures
may also increase the risk of the heart infection occurring. Giving children
with heart defects an antibiotic by mouth before these procedures can help
prevent bacterial endocarditis. It is important that you inform all medical
4


personnel that your child has a VSD so they may determine if the antibiotics
are necessary before a procedure.
Cardiac Catheterization — Your child's VSD may be repaired surgically in
the operating room or by a cardiac catheterization procedure. One method
currently being used to close some VSDs is the use of a device called a septal
occluder. During this procedure, the child is sedated and a small, thin, flexible
tube is inserted into a blood vessel in the groin and guided into the heart.
Once the catheter is in the heart, the cardiologist will pass the septal occluder
into the VSD. The septal occluder closes the ventricular septal defect
providing a permanent seal.
Surgical Repair — Some types of VSDs will close on their own with time.
Many, however, are too large or are positioned such that they cannot close on
their own and require surgical closure. The surgical closure of a VSD is
carried out through an incision in the middle of the chest. The breast bone is
split in the middle and spread apart to expose the heart. A heart-lung
machine is used to do the work of the heart while the heart is cooled,
stopped, emptied and opened, usually through the right atrium. The hole in
the wall between the right and left ventricles is closed by sewing to it a patch
of Dacron cloth or a patch of thin leather-like material called pericardium. The
heart is then closed and restarted as the heart-lung machine is withdrawn.
Advancements in cardiovascular surgical repair include minimally invasive
cardiac surgery.
Source: Children’s Hospital, Boston Cardiology Website, Accessible at:
http://www.childrenshospital.org/az/Site500/printerfriendlypageS500P0.html
5