A rare cause of abnormal pulmonary venous drainage: septum primum malposition.

Septum primum malposition should be kept in mind during the imaging of complex CHDs specifically during the segmental analysis of the pathologies with heterotaxy syndromes; it should be differentiated from other aetiologies of abnormal pulmonary venous drainage as accurate diagnosis would facilitate the ideal surgery in these complex pathologies requiring a detailed preoperative preparation.