Normally, blue or low oxygen blood returns from the body and is pumped out to the lungs.
Red, or oxygenated blood returns from the lungs and is pumped out to the body.
Tetralogy of Fallot is made up of four problems that result in not enough blood flow to the
lungs.
Complete surgical repair consists of removing the pulmonary valve, and opening up the narrowed
area out to the lungs by using a patch material.
Also, the hole between the bottom chambers of the heart is closed.
This allows separation of red and blue blood, and augments blood flow to the lungs.
Unfortunately, removing the valve allows leaking of blood backwards which over time, results
in stretching and weakening of the right ventricle.