The most common cause of high blood pressure in infants
is kidney disease. Since your daughter has congenital heart
disease, it would be important to ensure that she doesn’t also have an associated coarctation, or obstruction, of the aorta, the main artery that takes blood from the left side of the heart out to the head, neck, and rest of the body. This should have been evaluated by an echocardiogram when the rest of the heart was seen.