D-Transposition of the Great Vessels
Also
known as: D-TGV, cyanotic
What
is it?
In
transposition of the great vessels (arteries), the
two main arteries of the heart are reversed in
position, so the aorta is connected to the right
pumping chamber (right ventricle) and the
pulmonary artery is attached to the left pumping
chamber (left ventricle). Normally, the pulmonary
artery carries oxygen-poor (blue) blood from the
right ventricle to the lungs, and the aorta
normally carries oxygen-rich (red) blood from the
left ventricle to the body.
Infants
born with transposition can survive only if they
have one or more connections to allow the blue and
red blood to mix. These include a hole between the
two upper chambers (an atrial septal defect), a
hole between the two lower chambers (a ventricular
septal defect), or a vessel connecting the lung
artery with the aorta (a patent ductus arteriosus).
Who
gets it?
Patients are born with transposition of the great
vessels, and it is the most common form of
cyanotic heart disease in newborns.
What
causes it?
In the
developing fetus, the pulmonary artery and the
aorta failed to line up properly, resulting in
transposition of the great vessels. In normally
developing fetus with normal anatomy, the left
ventricle experiences a rapid increase in mass
secondary to both volume and pressure work loads.
In transposition, this transition is absent or
directed to the right ventricle. No one knows what
causes it.
What
are the symptoms?
Symptoms of transposition of the great vessels
include the newborn looking blue (cyanotic) right
after birth because their blood is not mixing
enough to provide sufficient oxygen. Sometimes
babies with this condition will have heart
murmurs, and an x-ray will detect a cardiac
enlargement and pulmonary over circulation. If
left untreated, the baby’s condition will
deteriorate and heart failure can occur in as
little as 24 to 48 hours after birth.
How is
it diagnosed?
A
doctor may diagnose transposition of the great
vessels by first using an oxygen monitor to detect
if the oxygen level in the blood is low. A doctor
may make an exact diagnosis by doing an
echocardiogram, a procedure that uses ultrasound
to produce images of the structure of the heart.
The test can also demonstrate the branching
pattern of the coronary arteries.
What
is the treatment?
Treatment for the newborn diagnosed with
transposition of the great vessels is critical.
Without it, about half of newborns with the
condition will die by one month of age and 90
percent die within one year. The doctor may
initially perform a procedure called an atrial
septostomy. By using cardiac catheterization, the
doctor will thread a tube through a blood vessel
to create an opening or enlarge an existing hole
between the two upper chambers. In some cases, a
medication (prostaglandin) is given to enlarge or
open the small tube between the aorta and the
pulmonary artery (the PDA).
There
are two types of surgery a doctor may perform to
correct the condition. In the first, the doctor
creates a tunnel, or baffle, inside the upper
chambers of the heart to redirect the red blood to
the right ventricle and the blue blood to the left
ventricle. Called a venous switch or intra-atrial
baffle procedure, it is usually performed early in
infancy.
In the
second procedure, the doctor detaches the major
arteries from the heart, switches them, and sews
them back to the heart in the proper position. The
aorta is connected to the left ventricle and will
pump red blood to the body and the pulmonary
artery will pump blue blood to the lungs. Called
an arterial switch procedure, it must be performed
within the first few days or weeks after birth.
Self-care tips
Occasionally, problems with heart rhythm or
function can occur, but overall results of surgery
for transposition of the great vessels is
excellent Children who have had a successful
repair of the condition generally lead normal,
healthy lives, however they need to visit a
cardiologist at least once a year for the rest of
their lives. They also need to take antibiotics to
prevent infection of the heart when having dental
work and other procedures.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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