Tetralogy of Fallot can be defined as a congenital heart defect.
Here, four related heart defects change the way blood flows to the
lungs and through the heart which are as follows :
- Ventricular septal
defect can be dedined as a hole in the septum, or wall,
separating the two ventricles, of the heart. The septum under
normal circumstances acts as a barrier that prevents blood from
both sides of the heart from mixing. But in the presence of VSD,
the high-oxygen blood from the left ventricle and the low-oxygen
blood from the right ventricle can mix. This can lead to either too
little or too much blood flow going to the lungs.
- Pulmonary
stenosis,can be defined as a narrowing or thickening of
the valve that connects the right ventricle to the pulmonary
artery.
In case of pulmonary stenosis, the heart has to work harder in
order to pump blood to the lungs. There is also less blood
traveling to the lungs because the pathway is narrowed. This leads
to less blood becoming red, oxygen-rich blood.
- Right ventricular
hypertrophy can be defined as thickening of the muscular
wall of the right ventricle. The thickened wall leads to blocking
of the flow of blood through the pulmonary valve, which allows
blood from the heart to flow into the lungs.
- An "overriding
aorta," which means the artery that carries high-oxygen
blood to the body is out of place and arises above both ventricles,
instead of just the left ventricle, as in a healthy heart. This
allows some blood that is low in oxygen to flow into the aorta and
out to the body, instead of to the pulmonary artery, which would
normally take it to the lungs to pick up oxygen.