Transposition of the Great Arteries (TGA/TGV)
This is the CHD that I was born wtih.
Transposition of the Great Arteries is one of the most common cyanotic CHDs. Sixty to 70 percent of the infants born with the defect are boys.
TGA occurs in 5 –7 % of all CHD…that is approximately 20 – 30 incidences per 100,000 live births
For
no clear reason, the heart develops abnormally in the first 8 weeks of
pregnancy. With TGA, the aorta arises from the right ventricle and the
pulmonary artery arises from the left ventricle…the exact opposite of a
normal heart's anatomy. (see photo below).
Infants
often appear cyanotic (blue) within days of life. The degree of
cyanosis depends on the presence and degree of other defects (like an
ASD that may allow for some mixing of the blood). Symptoms may include:
- Rapid, labored breathing
- Rapid heartbeat
- Cool, clammy skin
- Poor appetite
A diagnosis may be made from one or several of the following:
- Chest x-ray – takes pictures on film and shows images of internal tissues and organs
- Electrocardiogram EKG/ECG - tests electrical activity and shows abnormal rhythms
- Echocardiogram – uses sound waves and evaluates structure and function of heart
- Cardiac
catherisation - an invasive procedure that takes blood pressures and oxygen
measurements in the 4 chambers of the heart and the pulmonary artery
and aorta. During cath, a contrast dye can be injected to clearly
visualize structures inside the heart
Infants born with TGA can
only survive if there is a shunt between the 2 sides of the heart.
Frequently, infants born with TGA may also have a VSD or ASD which
allows for mixing of the blue and red blood (known as purple blood).
This mixing is often not adequate enough to meet the body's demands for
oxygen. The child will most likely be administered prostaglandins
(medicines that prevent the ductus arteriosus from closing therefore
allowing mixing of blood). A "balloon atrial septostomy" may be
performed to enlarge or stretch the foramen ovale (a connection between
the left and right atrium that allows for mixing of blood) and thus
creating a large ASD. Once safe oxygen levels and stable cardiac and
pulmonary function is established, the child will need corrective
surgery.
Further treatment will be based on the child's age,
overall health, medical history, extent of disease, tolerance to
medications and procedures and the expectations for the course of the
disease.
Doctors may proceed with one of the following surgeries:
Arterial
Switch – This is the most commonly used method and is performed within
the first month of life. During this procedure, the aorta is moved to
the right ventricle and the pulmonary artery is moved to the left
ventricle. The coronary arteries are also moved so that they will
originate from the aorta and take oxygen rich blood to the heart. Other
defects that may be present (ASD, VSD) will be closed.
Atrial
Switch (Mustard or Senning operation) – A tunnel (also called a baffle)
is made between the 2 upper chambers (atria) thus diverting oxygen rich
blood to the right ventricle and aorta. The right ventricle will then
pump blood to the entire body instead of just to the lungs as in a
normal heart. This procedure was most commonly used during the 1960s –
1980s. However, this procedure has proven to have more long term
complications such as arrythmias, baffle obstructions or leaks, heart
valve leaks and decreased right ventricle function. Often, this
procedure is used only when complications (such as narrowing of
pulmonary valve) are present.
During the past 40 years, the
survival rate for a newborn with TGA has improved remarkably from less
than 10% within the first year of life to about 90% to the age of 20
years.
Consult you or your child's physician regard the specific outlook for you or your child.
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..
Thanks to Vanessa at C.H.D. HEARTS - Hope for more tomorrows (CHD Heart Foundation)
Related LinksThe 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 Transposition of the Great Arteries.
http://www.bhf.org.uk/publications/view_publication.aspx?ps=1000802