Congenital heart defects are abnormalities in the heart’s structure
that are present at birth. Approximately one out of every 100 newborns
have congenital heart defects ranging from mild to severe, making it
the most common birth defect in the United States. Congenital heart
defects happen because of incomplete or abnormal development of the
fetus’ heart during the very early weeks of pregnancy. Some are known
to be associated with genetic disorders but the cause of most congenital
heart defects is unknown. While they can’t be prevented, there are
many treatments for the defects and any related health problems. Today
there are more treatment options for congenital heart defects than
ever before, and most defects are treated successfully.
Common congenital heart defects include:
(read more by clicking on a defect name)
- Aortic or Pulmonary Stenosis
In aortic stenosis, the aortic valve is stiffened and has a narrowed opening (a condition called stenosis). It does not open properly, which increases strain on the heart because the left ventricle has to pump harder to send blood out to the body. Sometimes the aortic valve also does not close properly, causing it to leak, a condition called aortic regurgitation. 
- Atrial Septal Defect (ASD)
ASD is a hole in the wall (called the septum) that separates the left atrium and the right atrium.
- Atrioventricular Canal Defect
This defect - also known as endocardial cushion defect or atrioventricular septal defect - is caused by a poorly formed central area of the heart. Typically there is a large hole between the upper chambers of the heart (the atria) and, often, an additional hole between the lower chambers of the heart (the ventricles). Instead of two separate valves allowing flow into the heart (tricuspid on the right and mitral valve on the left), there is one large common valve, which may be quite malformed. Atrioventricular canal defect is commonly seen in children with Down syndrome.
- Coarctation of the Aorta
This is a narrowing of a portion of the aorta, and often seriously decreases the blood flow from the heart out to the lower portion of the body.
- Hypoplastic Left Heart Syndrome
When the structures of the left side of the heart (the left ventricle,
the mitral valve, and the aortic valve) are underdeveloped, they
are unable to pump blood adequately to the entire body. This condition
is usually diagnosed within the first few days of life, at which
point the infant may be critically ill. Fortunately, many of these
infants are recognized to have serious heart disease on prenatal
imaging tests.
- Patent
Ductus Arteriosis (PDA)
The ductus arteriosus (DA) is a normal blood vessel in the developing
fetus that diverts circulation away from the lungs and sends it
directly to the body. (The lungs are not used while the unborn
fetus is in amniotic fluid - the fetus gets oxygen directly from
the mother's placenta.) The DA usually closes on its own shortly
after birth; it is no longer needed once a newborn breathes on
his own. If the DA doesn't close, then a condition called patent
ductus arteriosus (PDA) results, which can result in too much blood
flow to a newborn's lungs. PDA is common in premature babies.
- Pulmonary
Atresia
ASD is a hole in the wall (called the septum) that separates the
left atrium and the right atrium.
- Tetrology
of Fallot (TOF)
Tetralogy of Fallot is actually a combination of four heart defects.
It includes pulmonary stenosis, a thickened right ventricle (known
as ventricular hypertrophy),a hole between the lower chambers (known
as a ventricular septal defect), and an aorta that can receive
blood from both the left and right ventricles, instead of draining
just the left. Because deoxygenated (blue) blood can flow out to
the body, children with this defect often appear bluish.
- Transposition
of the Great Arteries
In this condition, the pulmonary artery and the aorta (the major blood vessels leaving the heart) are switched so that the aorta arises from the right side of the heart and receives blue blood, which is sent right back out to the body without becoming oxygen-rich. The pulmonary artery arises from the left side of the heart, receives red blood and sends it back to the lungs again. The result is that babies with this condition often appear very blue and have low oxygen levels in the bloodstream. They usually come to medical attention within the first days of life.
- Tricuspid
Atresia
Blood normally flows from the right atrium to the right ventricle through the tricuspid valve. In tricuspid atresia, the valve is replaced by a plate or membrane that does not open. The right ventricle therefore does not receive blood normally and is often small.
- Truncus Arteriosus
In an embryo, the aorta and the pulmonary artery are initially a single vessel. During normal development, that vessel splits to form the two major arteries. If that split does not occur, the child is born with a single common great blood vessel called the truncus arteriosus. There is usually a hole between the ventricles associated with this defect.
- Ventricular Septal Defect (VSD)
One of the most common congenital
heart defects, VSD is a hole in the wall (septum) between the heart's
left and right ventricles. These can occur at different locations
and vary in size from very small to very large. Some of the smaller
defects may gradually close on their own.
It can be frightening to learn that your child has a congenital heart
defect (one that’s present at birth). Medical knowledge, technology,
and experience can offer accurate diagnosis and treatments that allow
nearly every form of congenital heart defect to be treated. Although
nothing can be guaranteed with 100% certainty, most kids with heart
problems can enjoy happy and healthy futures.
