Tetralogy of Fallot
In medicine, the Tetralogy of Fallot (described by Fallot, Etienne, 1850 - 1911, Marseille) is a significant and complex Congenital heart defect, involving four different heart malformations:
- A ventricular septal defect (VSD), a hole between the two bottom chambers (ventricles) of the heart.
- Right ventricular outflow tract obstruction, a narrowing at or just below the pulmonary valve.
- The aorta is positioned over the ventricular septal defect instead of in the left ventricle.
- The right ventricle is more muscular than normal.
Pseudotruncus arteriosus is a particularly severe variant of the tetralogy of Fallot, in which there is complete obstruction of the right ventricular outflow tract. In these individuals, there is complete right to left shunting of blood. The lungs are perfused via collaterals from the systemic arteries. These individuals are severe cyanotic and will have a continuous murmur on physical exam due to the collateral circulation to the lungs.
Pathophysiology
The tetralogy of Fallot results in low oxygenation of blood. It is often evidenced by a bluish tint to the baby's skin. But there are "pink Fallots" too when only low blood with low oxygenation is in the body.
Treatment
The condition was initially thought untreatable until Dr. Alfred Blalock (Baltimore, 1899 - 1964), assisted by Vivien Thomas, (or, arguably, Vivien Thomas assisted by Dr. Blalock) developed a procedure to alleviate the condition. The surgery involved joining an artery leaving the heart to an artery leading to the lungs, in an attempt to give the blood a second chance at oxygenation. This first blue baby operation came to be known as the Blalock-Taussig Shunt. The idea of this procedure came from Helen B. Taussig (there is some historical dispute over exactly where priority and credit should be given, as Blalock, Thomas, and Taussig have each given different accounts which are difficult to confirm). (The term Blue Baby Syndrome is sometimes applied to the tetralogy of Fallot, but is less specific and includes other conditions.)
The procedure of treatment is to enlarge the pulmonary valve und close the ventricular septal defect in that way, that the aorta gets all blood from the left ventricle.
The children feel well after this procedure und usually grow normally but they have to stay under control all their life.
