Tetralogy of Fallot: Key Features
Tetralogy of Fallot has four key features:
Ventricular septal defect
- an opening in the ventricular septum or dividing wall between the two lower chambers of the heart known as the right and left ventricles. This hole allows the oxygen-poor (blue) blood to mix with the oxygen-rich (red) blood.
Pulmonary stenosis
- abnormal narrowing of the opening into the pulmonary artery from the right ventricle. This narrowing blocks the blue blood from reaching the lung.
Right ventricular hypertrophy
- thickening of the anterior right ventricular wall and the septum while cavity size is usually normal or slightly enlarged. The muscular wall becomes thickened from overwork while the heart needs to pump harder against the resistance caused by the pulmonary stenosis.
Dextroposition or Overriding aorta
- the aorta is shifted towards the right side of the heart so that it sits over the ventricular septal defect which causes blood to flow into the aorta from both the right and left ventricles.
