Coarctation of the aorta is a narrowing or constriction of a segment of the aorta.

In utero, the ductus arteriosus (DA) serves to divert ventricular output away from the lungs and toward the placenta by connecting the main pulmonary artery to the descending aorta. A patent ductus arteriosus (PDA) in the first 3 days of life is a physiologic shunt in healthy term and preterm newborn infants, and normally is substantially closed within about 24 hours after bith and completely closed after about three weeks. Failure of physiologcal closure is referred to a persistent or patent ductus arteriosus (PDA). Depending on the degree of left-to-right shunting, PDA can have clinical consequences.

An anomaly of the intra-atrial or intraventricular septum.

Any structural anomaly of the heart and blood vessels.

Impairment of gas exchange within the lungs secondary to a disease process, neoplasm, or trauma, possibly resulting in hypoxia, hypercarbia, or both, but not requiring intubation or mechanical ventilation. Patients are normally managed with pharmaceutical therapy, supplemental oxygen, or both.

A congenital absence or considerable underdevelopment of the trachea such that communication between the larynx proximally and the alveoli of the lungs distally is lacking.

Bilateral lack of development of the lungs.