Why do babies with tetrology of fallot have blood more lactic acid than a normal baby?

Tetralogy of Fallot (TOF) is a congenital heart defect that affects the normal flow of blood through the heart. It consists of four abnormalities: a hole between the ventricles (ventricular septal defect), an obstruction in the right ventricular outflow tract (pulmonary stenosis), an overriding aorta, and hypertrophy of the right ventricle.

Due to the obstruction in the right ventricular outflow tract, the blood flow to the lungs is reduced. This leads to a condition called cyanosis, where the skin and mucous membranes appear bluish due to low oxygen levels in the blood.

In response to the reduced oxygen levels, the body produces more red blood cells in order to carry more oxygen. This condition is called polycythemia. The increased number of red blood cells makes the blood thicker and more viscous, which can lead to problems such as clotting and stroke.

In order to compensate for the increased viscosity of the blood, the body produces more lactic acid. Lactic acid is a waste product of anaerobic metabolism, which is the process of breaking down glucose for energy without the use of oxygen. The increased production of lactic acid leads to a condition called acidosis, where the blood becomes more acidic.

The acidosis can cause a number of problems, such as decreased heart function, increased bleeding, and damage to the liver, kidneys, and brain. In severe cases, acidosis can be fatal.