If a baby with tricuspid atresia doesn't have an atrial septal defect, the baby may need a procedure to create this opening.

CNN: Tricuspid atresia

This hole is either a heart defect (atrial septal defect) or an enlarged natural opening (foramen ovale) that is supposed to close soon after birth.

CNN: Tricuspid atresia

When Dr. Lillehei was putting these patches in the children to close the ventricaluar septal defect, there's a critical nerve that runs right along that hole, and it's invisible.

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