Transposition of the great arteries is a serious but rare heart defect present at birth (congenital), in which the two main arteries leaving the heart are reversed (transposed). The condition is also called dextro-transposition of the great arteries.
2. INTRODUCTION
Transposition of the great arteries is a
congenital (present at birth) heart defect.
Due to abnormal development of the fetal
heart during the first 8 weeks of pregnancy,
the large vessels that take blood away from
the heart to the lungs, or to the body, are
improperly connected.
3.
4. Transposition of the Great
Arteries
Most common form of
cyanotic congenital heart
disease (5 to 7% of all
congenital heart defects )
which presents in the
newborn period.
More common in males
Babies are usually normal
birth weight and size.
1. Aorta emerges from RV 5. PDA
2. PA emerges from LV
3. VSD
4. ASD
5. In transposition of the great arteries, the aorta is
connected to the right ventricle, and the
pulmonary artery is connected to the left ventricle
- the exact opposite of a normal heart's anatomy.
Oxygen-poor (blue) blood returns to the right
atrium from the body, passes through the right
atrium and ventricle, then goes into the
misconnected aorta back to the body.
Oxygen-rich (red) blood returns to the left atrium
from the lungs, passes through the left atrium and
ventricle, then goes into the pulmonary artery and
back to the lungs.
6. Two separate circuits are formed - one that
circulates oxygen-poor (blue) blood from the body
back to the body, and another that recirculates
oxygen-rich (red) blood from the lungs back to the
lungs.
Because of the low amount of oxygen provided to
the body, TGA is a heart problem that is labeled
"blue-baby syndrome.“
Associated heart abnormalities: they actually
may be necessary in order for an infant with
transposition of the great arteries to live.
Ventricular septal defect – the most common
Left ventricular outflow tract obstruction.
Atrial septal defect
Patent ductus arteriosus
7. CAUSES:
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 of the time this
heart defect occurs sporadically (by chance), with
no clear reason for its development.
8. Physical Findings:
Indication of TGA is a newborn who becomes
cyanotic (blue) in the transitional first day of
life when the maternal source of oxygen (from
the placenta) is removed.
Cyanosis is noted in the first hours of life in
about half of the infants with TGA, and within
the first days of life in 90 percent of them.
The degree of cyanosis is related to the presence
of other defects that allow blood to mix,
including a PDA- cyanosis, seen in lips and
under fingernail beds – may not be present.
9. Physical Findings:
Congestive heart failure will develop because
of the extra blood flow going to the lungs.
Consistent with CHF = there is poor feeding,
poor weight gain, sweating, and fast or labored
breathing, rapid heart rate ,cool, clammy skin
Cyanosis will not improve with the application
of oxygen – if it does, then the problem is
pulmonary, not cardiac.
The second heart sound is loud and single
heart murmur, depending if there is a VSD or
not
10. WHY IS TRANSPOSITION OF THE GREAT
ARTERIES A CONCERN?
The right ventricle, connected to the aorta in
TGA, is the weaker of the two ventricles.
Because the right ventricle is weaker, it may
not be able to pump blood efficiently to the
body, and it will enlarge under the strain of
the job.
The left ventricle may pump blood into the
lungs more vigorously than needed, leading
to strain in the blood vessels in the lungs.
11. History & Physical findings
chest x-ray
electrocardiogram (ECG or EKG)
echocardiogram (echo) , if not 100% definitive Cardiac
Cath
cardiac catheterization - 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.
DIAGNOSIS:
12. TREATMENT
BASED ON:
Child's age, overall health, and medical history
Extent of the disease
Child's tolerance for specific medications, procedures, or
therapies
Expectations for the course of the disease
Opinion or preference of parents
Combination of defects that accompany the primary
problem of TGA.
Development of early pulmonary vascular disease is also
common. The changes associated with PVD can occur as
early as a few weeks of life and tend to occur more
frequently in babies who have ventricular septal defects in
addition to TGA. Early corrective surgery minimizes the
chances of development of PVD.
13. 1)As part of the cardiac catheterization, a procedure called
BALLOON ATRIAL SEPTOSTOMY may be
performed to improve mixing of oxygen-rich (red) and
oxygen-poor (blue) blood.
BALLOON ATRIAL SEPTOSTOMY
A special catheter with a balloon in the tip is used to
create an opening in the atrial septum (wall between the
left and right atria).
The catheter is guided through foramen ovale (a small
opening present in the atrial septum that closes shortly
after birth) and into left atrium.The balloon is inflated.
The catheter is quickly pulled back through the hole,
into the right atrium, enlarging the hole, allowing blood
to mix between the atria.
TREATMENT
14. BALLOON ATRIAL SEPTOSTOMY
A special catheter with a balloon in the tip is used to
create an opening in the atrial septum (wall between
the left and right atria).
The catheter is guided through the foramen ovale (a
small opening present in the atrial septum that
closes shortly after birth) and into the left atrium.
The balloon is inflated.
The catheter is quickly pulled back through the
hole, into the right atrium, enlarging the hole,
allowing blood to mix between the atria.
2) PROSTAGLANDIN E1 :An intravenous
medication called prostaglandin E1 is given to keep
the ductus arteriosus from closing.
15.
16. SURGICAL PROCEDURES:
ARTERIAL SWITCH:
• The aorta and pulmonary artery are divided
and reconnected so that the pulmonary artery
is connected to the right ventricle and
supplies deoxygenated blood to the lungs.
• The aorta is connected to the left ventricle
and supplies oxygenated blood to the body.
• The coronary arteries are also relocated so
that they will receive oxygenated blood from
the aorta.
• Any septal defects are closed at the same
time
18. MUSTARD OR SENNING OPERATION
If the baby is older at the time of diagnosis
or there is an unusual location of one of the
coronary arteries, the surgeon may choose
to perform an atrial switch operation called
a Mustard or Senning operation.
For this operation the heart/lung bypass
machine is used.The venous drainage of
blood coming into the heart is rerouted
rather switching the arteries that carry blood
out of the heart.
.
19. In this case :
1) the blue blood returning to the right atrium is
redirected to the left atrium, flows to the left
ventricle where it is pumped through the
pulmonary arteries to the lungs.
2) Red blood returning from the lungs is baffled
to the right atrium , flows to the right ventricle
where it is pumped through the aorta and out to
the body. Even though the blood goes to the
right location, the heart remains configured so
the right ventricle pumps blood to the body and
the left ventricle pumps blood to the lungs
MUSTARD OR SENNING OPERATION
20. Long-term complications of the Mustard
procedure:
Systemic heart failure
Arrhythmias
Venous return stasis
Pulmonary edema
Sudden death
MUSTARD OR SENNING OPERATION
22. Transposition of the Great Arteries
1. Deoxygenated blood redirected to LA
2. LV Lungs
3. Oxygenated blood from lungs redirected to RA
4. RV Body
23. RASTELLI PROCEDURE:
• Performed for TGA with left ventricular outflow
obstruction
• The ventricular septal defect is closed in such a way that
the left ventricle is connected to the aorta and the right
ventricle is connected to the lungs using a conduit with a
valve in it.
• One end of the conduit is connected to the right ventricle
where blood exits into the pulmonary artery and the other
end is attached to the pulmonary artery
• The conduit acts a bypass around the naturally occurring
narrowing. This conduit will need to be replaced as the
child grows. Usually this is not necessary for 3 to 5 years
after the original operation if done in infancy and then 1 to
2 more times throughout the child's life.
SURGICAL PROCEDURES:
24. 1. VSD closed with patch
2. Conduit
RASTELLI PROCEDURE:
25. POSTOPERATIVE CARE FOR YOUR
CHILD:
After surgery, infants will return to the
intensive care unit (ICU) for a few days to
be closely monitored during recovery.
While child is in the ICU, special
equipment will be used to help him/her
recover, and may include the following:
ventilator –It breathes for the child while
he/she is too sleepy to breathe effectively on
his/her own. After surgery, children will
benefit from remaining on the ventilator
overnight or even longer so they can rest.
26. Centralvenous (IV) catheters - provide IV fluids and
important medicines that help child recover from the
operation.
arterial line - measures blood pressure continuously
during surgery and while child is in the ICU.
nasogastric (NG) tube - keeps the stomach drained of
acid and gas bubbles that may build up during surgery.
urinary catheter - drain out of the bladder and
accurately measures how much urine the body makes,
which helps determine how well the heart is
functioning.
chest tube –
heart monitor -
POSTOPERATIVE CARE FOR YOUR
CHILD:
27. 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 fluid from the body.
Some infants are just tired, and need to build their strength up
before they will be able to learn to bottle feed. Strategies include :
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
that can either supplement or take the place of bottle-feedings.
Infants too tired - feeding tube alone.
POSTOPERATIVE CARE FOR YOUR CHILD:
28. Long-term outlook after TGA surgical repair:
Many infants who undergo TGA surgical repair will
grow and develop normally. However, after TGA
repair, infant will need to be followed periodically by
a pediatric cardiologist who will make assessments to
check for any heart-related problems, which include :
fast, slow, or irregular heart rhythms
leaky heart valves
narrowing of one or both of the great arteries at the
switch connection site(s)
narrowing of the coronary arteries at their switch
connection site