Cyanotic Congenital Heart Defects
Cyanosis is the bluish or purplish discoloration
of the skin due to deficient oxygenation
of the blood. Babies born with cyanotic
defects will have a bluish tinge to their
skin and nails ("blue babies").
Cyanotic heart defects occur when deoxygenated
blood from the right side of the heart enters
the left side of the heart rather than first
traveling to the lungs to be oxygenated.
There are several types of cyanotic congenital
defects. They include:
Hypoplastic
Left Heart Syndrome
In hypoplastic left heart syndrome, the
left side of the heart is underdeveloped.
This includes the entire left side: the
aorta,
aortic valve,
left ventricle
and mitral
valve. When this happens, blood returning
from the lungs flows through an opening
in the wall between the atria (atrial septal
defect). The right ventricle pumps the blood
into the pulmonary
artery, and blood reaches the aorta
through a patent
ductus arteriosus.
Infants born with hypoplastic left heart
syndrome will have surgery to help treat
the defects. Surgery may include:
- The Norwood procedure - This procedure
allows the right ventricle to pump blood
to both the lungs and the body. It must
be performed soon after birth.
- Fontan operation - This procedure attempts
to create a connection between the veins
returning oxygenated blood to the heart
and the pulmonary artery.
- Heart transplant - This procedure provides
a normally structured heart for the infant.
Routine follow-up is important for adults
with repaired hypoplastic left heart syndrome.
Medications may be prescribed to prevent
blood clots and maintain normal heart rhythm.
Surgical revision of the Fontan connection
or catheterization
may be necessary. Patients also are at risk
for bacterial endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
Pulmonary Atresia
Pulmonary atresia is the absence of the
heart’s pulmonary
valve. In the absence of this valve,
blood can't flow from the lower right side
“pumping” chamber (ventricle)
into the pulmonary
artery and to the lungs. The right ventricle
may stay small and undeveloped. The tricuspid
valve also is often poorly developed.
To survive, an opening in the atrial septum
lets blood exit the right atrium so deoxygenated
blood can mix with oxygenated blood in the
left atrium. The left ventricle pumps this
blood into the aorta
and out to the body. The only source of
blood flow to the lungs is the patent
ductus, an open passageway between the
pulmonary artery and the aorta. Infants
born with pulmonary atresia will have surgery
to correct the defect.
Individuals with surgically repaired pulmonary
atresia require lifelong follow-up care
by experienced cardiologists. Patients also
are at risk for bacterial endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
Tetralogy
of Fallot (TOF)
Tetralogy of Fallot is the most common form
of cyanotic congenital heart disease. It
represents approximately 10% of cases of
congenital heart disease in the U.S. It
has four components:
- A large hole (ventricular
septal defect)
lets
blood pass from the right to the left
ventricle without going through the
lungs.
- A narrowing (stenosis) at or just beneath
the pulmonary valve. The stenosis partially
blocks the blood flow from the heart's
right side to the lungs.
- The right ventricle
is more muscular than normal.
- The aorta
lies directly over the ventricular
septal defect.
Most patients with TOF require surgery
early in childhood. Surgical repair involves
closing the ventricular
septal defect and relieving obstruction between the
right ventricle and pulmonary
artery.
Individuals with surgically repaired TOF
require lifelong follow-up care by experienced
cardiologists. Repair of pulmonary valve
stenosis may produce a leak in the pulmonary
valve (pulmonary regurgitation). Follow-up
care after surgical repair may need to
include treatment of arrhythmias and regurgitation.
Cardiac repair during adulthood is rarely
necessary, but sometimes is necessary if
significant obstruction remains or a ventricular
septal defect is present. In some cases,
pulmonary valve replacement may be necessary.
Transposition of
the Great Arteries
Affecting approximately 40 out of 100,000
infants, transposition of the great arteries
is the most common cyanotic heart defect
identified in the first week of life. In
this defect, the positions of the pulmonary
artery and the aorta
are reversed. The aorta is connected to
the right ventricle,
allowing de-oxygenated blood returning to
the heart to pump back out without being
re-oxygenated by the lungs. In addition,
the pulmonary artery is connected to the
left ventricle, allowing blood from the
lungs to return back to the lungs. Most
patients with congenitally corrected transposition
of the great vessels also have other associated
defects, such as a ventricular
septal defect and/or pulmonary stenosis.
Infants born with transposition of the
great arteries will have surgery to correct
the defects. The aorta and pulmonary artery
are reconnected to the correct ventricles.
Lifelong follow-up care by experienced cardiologists
is needed. Patients with surgically repaired
congenital transposition of the great arteries
also are at risk for bacterial endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
Two major types of surgery correct the
defects: atrial switch (Mustard or Senning
procedure) and an arterial switch.
- Atrial switch. This procedure creates
a tunnel (baffle) or atrial flaps between
the atria to redirect oxygenated blood
to the right ventricle and aorta and
the deoxygenated blood to the left ventricle
and the pulmonary artery.
- Arterial switch. In this procedure,
the aorta and pulmonary artery are switched
back to their normal positions. The coronary
arteries also are re-attached to the
new aorta.
Tricuspid Atresia
Tricuspid atresia is an uncommon form of
congenital heart defect. The term means
the absence of the tricuspid
valve. The result is a lack of blood
flow from the right upper “holding”
chamber (atrium) to the right lower “pumping”
chamber (ventricle). As a result, the right
ventricle is small and underdeveloped. To
survive, there typically is an opening in
the septal wall between the atria (atrial
septal defect) and an opening in the wall
between the two ventricles (ventricular
septal defect). Infants born with tricuspid
atresia will have surgery to correct the
defects.
Individuals with tricuspid atresia require
lifelong follow-up care by experienced cardiologists.
Patients also are at risk for bacterial
endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
Truncus Arteriosus
Truncus arteriosus is a rare and complex
ventricular
septal defect. When this occurs,
a single blood vessel exists where there
normally are two separate arteries arising
from the heart--the aorta
and the pulmonary
artery. This large, single great vessel
is called a truncus (trunk). It carries
blood to both the body and to the lungs.
Infants born with truncus arteriosus will
have surgery performed in early infancy
to close the ventricular septal defect and
separate blood flow to the body from blood
flow to the lungs. A patch is used to close
the ventricular defect. The pulmonary arteries
are then disconnected from the single great
vessel and a tube placed from the right
ventricle to the arteries.
Patients with truncus arteriosus need regular
follow-up care from experienced cardiologists
throughout life. Patients with repaired
truncus arteriosus have a higher risk for
heart rhythm disturbances (arrhythmias)
and a lessened ability for the heart muscles
to contract. Medication including diuretics,
agents to help the heart pump better and
drugs to control blood pressure and arrhythmias
may be necessary. Pulmonary hypertension
also may need to be treated.
Over time, the tube connecting the right
ventricle to the pulmonary artery may narrow
(stenosis). Surgery may be necessary to
replace the conduit. In addition, peripheral
pulmonary arteries also may become narrowed
and require surgery including catheterization
or stent.
The aortic valve sometimes becomes leaky
over time and may need to be replaced.
Patients with surgically repaired truncus
arteriosus also are at risk for bacterial
endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
Total Anomalous
Pulmonary Venous (P-V) Connection
In this congenital defect, the pulmonary
veins that bring oxygenated blood from the
lungs back to the heart drain through abnormal
connections to the right upper “holding”
chamber (atrium)
rather than to the left lower “pumping”
chamber (ventricle).
In the right atrium, oxygenated blood from
the pulmonary veins mixes with deoxygenated
blood arriving from the body. Part of this
mixture passes through the atrial septum
(atrial septal defect) into the left atrium.
It then enters the left lower “pumping”
chamber (ventricle),
to the aorta
and out to the body. The rest of the mixture
flows through the right ventricle, into
the pulmonary artery and to the lungs.
Infants born with total anomalous pulmonary
venous (P-V) connection will have surgery
to correct the defect.
Individuals with surgically repaired P-V
require lifelong follow-up care by experienced
cardiologists. Patients also are at risk
for bacterial endocarditis,
an infection of the heart’s valves
or inner lining (endocardium.) Before having
certain dental or surgical procedures performed,
it may be necessary to take preventive antibiotics.
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referral counselor.
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