AN 11-DAY-OLD female infant was brought to her physician because of screaming and irritability after feedings. A diagnosis of abdominal colic was made, and the infant's formula was changed. The postprandial screaming and irritability continued, and the mother sought a second opinion. The infant was now found to have lost weight and to have a rapid respiratory rate. The mother was told that the child might have a cardiac condition, and the infant was brought for further workup. A chest radiograph was obtained (Figure 1).
Denouement and Discussion
Coarctation of the Aorta
Coarctation of the aorta is a common congenital disorder of unknown origin and accounts for 6% of congenital anomalies.1 Martin et al2 have found that radiologists suggest coarctation infrequently, despite the well-described radiologic signs. A chest radiograph in this case showed a low aortic knob (Figure 2). The remainder of the radiograph was unremarkable. An echocardiogram