Subclavian and pulmonary steal phenomenon in isolated left subclavian artery with left lung agenesis.

Isolated left subclavian artery has been documented to be associated with several congenital cardiac defects, including tetralogy of Fallot and transposition of the great arteries. In some cases subclavian or pulmonary artery steal phenomenon may occur when the isolated left subclavian artery connects to the main pulmonary artery via a ductus arteriosus. The isolated left subclavian artery may be part of the cardiac manifestations in multiple congenital anomalies, such as VACTERL association. We describe subclavian and pulmonary steal phenomenon in a neonate with complex congenital heart disease, including an isolated left subclavian artery, and left lung agenesis. An isolated left subclavian artery is rare and its association with agenesis of the left lung has not been reported previously.