Definition for Tetralogy of Fallot
From Biology Forums Dictionary
Tetralogy of Fallot is a type of congenital heart defect. Congenital means that it is present at birth.
Tetralogy of Fallot causes low oxygen levels in the blood. This leads to cyanosis (a bluish-purple color to the skin).
The classic form includes four defects of the heart and its major blood vessels:
- Ventricular septal defect (hole between the right and left ventricles)
- Narrowing of the pulmonary outflow tract (the valve and artery that connect the heart with the lungs)
- Overriding aorta (the artery that carries oxygen-rich blood to the body) that is shifted over the right ventricle and ventricular septal defect, instead of coming out only from the left ventricle
- Thickened wall of the right ventricle (right ventricular hypertrophy)
