TET spells occur most often in children who have a congenital heart defect called Tetralogy of Fallot. Children with Tetralogy of Fallot have a combination of heart problems.

  • A ventricular septal defect (VSD), which is a hole between the two lower chambers of the heart.
  • Pulmonary stenosis (PS), which is a narrowing at or beneath the pulmonary valve.
  • Overriding aorta, in which the aorta lies directly above the VSD.
  • Thickening of the right ventricular wall.

Children having a TET spell may have several symptoms:

  • Rapid, deep breathing.
  • Fainting/loss of consciousness.
  • Increasing blueness (cyanosis) of the lips, tongue and nailbeds
  • Irritability or uncontrolled crying.

When does it happen?

TET spells may occur at any time. They happen most often after the child wakes in the morning or after a nap. They also may occur when the child is crying, feeding or after exercise.

What causes a TET spell?

A TET spell occurs when there is a sudden tightening of the narrowed area below the pulmonary valve. The blood that normally goes out of the pulmonary artery to the lungs, goes out of the aorta to the body instead. This makes the child look blue or bluer.

What should I do if this happens?

  • Put your child in a knee-chest position (on his stomach or on his side).
  • Call your child’s cardiologist or pediatrician.
  • If your child’s condition appears life threatening, call 911 or your local emergency medical system.

Source: Childrens Mercy Hospital