Left ventricular mid-cavity obstruction: A novel cause of duct-dependent systemic circulation in a newborn.

Accessory mitral valve tissue is a rare congenital anomaly that may cause left ventricular outflow tract obstruction. This may be the first case report in a neonate, describing accessory mitral valve tissue producing a significant left ventricular outflow tract obstruction, resulting in a duct-dependent systemic circulation perfusing the neck and head vessels. This report also discusses why a hybrid palliative strategy was adopted.