Isolated left subclavian with a compensatory ductus in a child with Tetralogy of Fallot

Tetralogy of Fallot is a cyanotic heart disease wherein aortopulmonary collaterals serve as source of pulmonary blood flow to maintain oxygenation. We report an incidentally detected isolated left subclavian artery supplying a compensatory ductus in a child with Tetralogy of Fallot that effectively contributed as a de novo palliative systemic to pulmonary artery shunt. Clinically, the entity could not be suspected, as the child did not have symptoms suggestive of arterial insufficiency of the left arm or weak pulses or neurological symptoms. The child underwent successful intracardiac repair with a reimplantation of left subclavian artery to left common carotid artery.