Congenital arteriovenous malformation between the subclavian artery and superior vena cava presenting in neonatal heart failure.

Congenital arteriovenous malformations are a well-described cause of neonatal heart failure. Fistulous connections are typically intrahepatic or intracranial. We present a case of a neonate with an intrathoracic arteriovenous malformation between the subclavian artery and superior vena cava resulting in florid neonatal heart failure. This unusual fistulous connection has only rarely been reported in the literature, and in those reports, it has not resulted in neonatal heart failure.