TOF

Children born with TOF have a combination of four cardiac anatomic characteristics:

1. Ventricular septal defect: There is a hole between the right and left pumping chambers (ventricles) of the heart.
2. Right ventricular outflow tract obstruction: The connection between the right ventricle and lung (pulmonary) artery is narrowed, and blood flow to the lungs is blocked. This is what causes babies to be blue.
3. Overriding aorta: The artery that connects the left ventricle to the body is positioned too far to the right.
4. Right ventricular hypertrophy: The right ventricle is thicker than normal, because it’s pumping against a blockage. It’s working too hard.