What is a ventricular septal defect?
A
ventricular septal 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. VSD is a congenital (present at birth) heart
defect. As the fetus is growing, something occurs to affect heart
development during the first 8 weeks of pregnancy, resulting in a VSD.
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, and 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.
Two basic types of VSD include the following:
- 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 14 to 17 percent of babies born each year.
The
heart is forming during the first 8 weeks of fetal development. It
begins as a hollow tube, then partitions within the tube develop 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.
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. Extra blood then passes through the pulmonary artery into
the lungs, causing higher pressure than normal in the blood vessels in
the lungs.
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.
Extra blood causes higher pressure in the blood vessels in the lungs.
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.
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 yet
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).
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. However, 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
The
symptoms of VSD may resemble other medical conditions or heart
problems. Always consult your child's physician for a diagnosis.
Your
child's physician may have heard a heart murmur during a physical
examination, and referred your child to a pediatric cardiologist for a
diagnosis. A heart murmur is simply a noise caused by the turbulence of
blood flowing through the opening from the left side of the heart to
the right.
A pediatric cardiologist
specializes in the diagnosis and medical management of congenital heart
defects, as well as heart problems that may develop later in childhood.
The cardiologist will perform a physical examination, listening to the
heart and lungs, and make other observations that help in the
diagnosis. The location within the chest where the murmur is heard
best, as well as the loudness and quality of the murmur (harsh,
blowing, etc.) will give the cardiologist an initial idea of which
heart problem your child may have. However, other tests are needed to
help with the diagnosis, and may include the following:
- Chest x-ray - a
diagnostic test which uses invisible electromagnetic energy beams to
produce images of internal tissues, bones, and organs onto film. With a
VSD, the heart may be enlarged because the right ventricle handles
larger amounts of blood flow than normal. Also, there may be changes
that take place in the lungs due to extra blood flow that can be seen
on an x-ray.
- Electrocardiogram (ECG or EKG) - a
test that records the electrical activity of the heart, shows abnormal
rhythms (arrhythmias or dysrhythmias), and detects heart muscle stress.
- Echocardiogram (echo) - a
procedure that evaluates the structure and function of the heart by
using sound waves recorded on an electronic sensor that produce a
moving picture of the heart and heart valves. An echo can show the
pattern of blood flow through the septal opening, and determine how
large the opening is, as well as much blood is passing through it.
- Cardiac catheterization - a
cardiac catheterization is an invasive procedure that gives very
detailed information about the structures inside the heart. Under
sedation, a small, thin, flexible tube (catheter) is inserted into a
blood vessel in the groin, and guided to the inside of the heart. Blood
pressure and oxygen measurements are taken in the four chambers of the
heart, as well as the pulmonary artery and aorta. Contrast dye is also
injected to more clearly visualize the structures inside the heart.
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
- expectations for the course of the disease
- 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. However, most
children 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: - digoxin - a medication that helps strengthen the heart muscle, enabling it to pump more efficiently.
- 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: - 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. - 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. However, 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 personnel that your child has a VSD so they
may determine if the antibiotics are necessary before a procedure. - Surgical Repair
The
goal is to repair the septal opening before the lungs become diseased
from too much blood flow and pressure. Repair is indicated for defects
that are causing symptoms, such as poor weight gain and rapid
breathing. Your child's cardiologist will recommend when the repair
should be performed based on echocardiogram and cardiac catheterization
results.
The operation is performed under general anesthesia.
Depending on the size of the heart defect and your physician's
recommendations, the
ventricular septal defect will be closed with
stitches or a special patch. Consult your child's cardiologist for more
information.- Interventional Cardiac Catheterization
Your
child's VSD may be repaired by a cardiac catheterization procedure. One
method currently being used to close some small muscular 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.
In
most cases, children will spend time in the intensive care unit (ICU)
after an VSD repair. During the first several hours after surgery, your
child will most likely be drowsy from the anesthesia that was used
during the operation, and from medications given to relax him/her and
to help with pain. As time goes by, your child will become more alert.
While your child is in the ICU, special equipment will be used to help him/her recover, and may include the following:
- Ventilator - a
machine that helps your child breathe while he/she is under anesthesia
during the operation. A small, plastic tube is guided into the windpipe
and attached to the ventilator, which breathes for your child while
he/she is too sleepy to breathe effectively on his/her own. Many
children have the ventilator tube removed right after surgery, but some
other children will benefit from remaining on the ventilator for a few
hours afterwards so they can rest.
- Intravenous (IV) Catheters - small,
plastic tubes inserted through the skin into blood vessels to provide
IV fluids and important medications that help your child recover from
the operation.
- Arterial line - a
specialized IV placed in the wrist, or other area of the body where a
pulse can be felt, that measures blood pressure continuously during
surgery and while your child is in the ICU.
- Nasogastric (NG) tube - a small, flexible tube that keeps the stomach drained of acid and gas bubbles that may build up during surgery.
- urinary catheter - a
small, flexible tube that allows urine to drain out of the bladder and
accurately measures how much urine the body makes, which helps
determine how well the heart is functioning. After surgery, the heart
will be a little weaker than it was before, and, therefore, the body
may start to hold onto fluid, causing swelling and puffiness. Diuretics
may be given to help the kidneys to remove excess fluids from the body.
- Chest tube - a
drainage tube may be inserted to keep the chest free of blood that
would otherwise accumulate after the incision is closed. Bleeding may
occur for several hours, or even a few days after surgery.
- Heart monitor - a
machine that constantly displays a picture of your child's heart
rhythm, and monitors heart rate, arterial blood pressure, and other
values.
Your child may need
other equipment not mentioned here to provide support while in the ICU,
or afterwards. The hospital staff will explain all of the necessary
equipment to you.
Your child will be kept as
comfortable as possible with several different medications; some which
relieve pain, and some which relieve anxiety. The staff may also ask
for your input as to how best to soothe and comfort your child.
After
discharged from the ICU, your child will recuperate on another hospital
unit for a few days before going home. You will learn how to care for
your child at home before your child is discharged. Your child may need
to take medications for a while, and these will be explained to you.
The staff will give you written instructions regarding medications,
activity limitations, and follow-up appointments before your child is
discharged.
Most
infants and older children feel fairly comfortable when they go home.
Pain medications, such as acetaminophen or ibuprofen, may be
recommended to keep your child comfortable. Your child's physician will
discuss pain control before your child is discharged from the hospital.
Often,
infants who fed poorly prior to surgery have more energy after the
recuperation period, and begin to eat better and gain weight faster.
After
surgery, older children usually have a fair tolerance for activity.
Your child may become tired quicker than before surgery, but usually
will be allowed to play with supervision, while avoiding blows to the
chest that might cause injury to the incision or breastbone. Within a
few weeks, your child should be fully recovered and able to participate
in normal activity.
You may receive additional instructions from your child's physicians and the hospital staff.
Most
children who have had a ventricular septal defect repair will live
healthy lives. Activity levels, appetite, and growth will return to
normal in most children. Your child's cardiologist may recommend that
antibiotics be given to prevent bacterial endocarditis for a specific
time period after discharge from the hospital.
Outcomes
also depend on the type of VSD, as well as how early in life the VSD
was diagnosed and whether or not it was repaired. With early diagnosis
and repair of a VSD, the outcome is generally excellent, and minimal
follow-up is necessary. When a VSD is diagnosed later in life, if
complications occur after surgical closure, or the VSD is never
repaired, the outlook is generally poor. There is a risk for developing
pulmonary hypertension (high blood pressure in the blood vessels of the
lungs) or Eisenmenger's syndrome. These individuals should receive
follow-up care at a center that specializes in congenital heart disease.
Consult your child's physician regarding the specific outlook for your child.
Related Links:
The British Heart Foundation are doing booklets for Parents of
children to help understand their childs heart and the booklets are
also for health professionals.
Here is the link for Ventricular Septal Defect
http://www.bhf.org.uk/publications/view_publication.aspx?ps=1000799
:Disclaimer: The
facts and opinions shown on this blog are as accurate and up to date as
possible, but are provided as general "information resources", which
may not be relevant to individual persons. This blog is not a
substitute for individual assessment and always take advice from a
doctor who is familiar with the particular person..