Congenital
Heart Disease
Congenital heart disease comprises a wide spectrum of
heart defects which may be present at the time of a person’s
birth.
The most common type of congenital defect is a hole in
the heart. This may occur between the two atria (an atrial
septal defect) or between the two ventricles (a ventricular
septal defect). Both conditions typically present themselves
in the form of heart murmurs which are abnormal sounds
produced by turbulence in the flow of blood through the
heart. A ventricular septal defect is generally more serious
than an atrial septal defect and, unless the hole in question
is very tiny, must be repaired.
Other examples of congenital heart disease include aortic
stenosis and Tetralogy of Fallot. In patients with the
former condition, the aortic valve (i.e. the valve which
separates the left ventricle from the aorta) is unusually
narrow. The left ventricle therefore has to work harder
to pump blood through the narrowed valve. Where the constriction
is severe, the supply of oxygenated blood to other parts
of the body may be considerably reduced.
As for Tetralogy of Fallot, it is a condition arising
from several different malformations of the heart, namely:
the narrowing of the pulmonary valve (pulmonary stenosis);
a hole in the wall between the ventricles (a ventricular
septal defect); and the “overriding” by the
aorta of the hole between the ventricles. As a result,
the aorta receives blood from both the left and right
ventricles. This in turn means that the blood which is
pumped out of the heart for distribution to other organs
is a mixture of oxygenated and deoxygenated blood, and
not oxygenated blood alone. Tetralogy of Fallot is usually
detected via the characteristic bluish tinge of affected
infants’ skin, a symptom arising from an insufficient
supply of oxygen-rich blood. |
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