Cyanosis in a patient after Fontan palliation due to unrecognised hepatic vein to coronary sinus communication.

A 6-year-old male with heterotaxia, abnormal systemic and pulmonary venous drainage, and a history of Fontan completion presented with desaturations and was found by cardiac catheterisation to have a hepatic vein to coronary sinus connection. This was successfully occluded using an Amplatzer Muscular Ventricular Septal Defect Occluder.