Coexistence of divided left atrium (cor triatriatum) and tetralogy of Fallot

The association of a partitioned left atrium (cor triatriatum) and tetralogy of Fallot has been reported a few times in the literature. In all of these cases, there was no clinical evidence of an obstructive lesion in the left heart, raising difficulties in establishing the proper diagnosis. We call attention to this rare combination of anomalies and to the particular morphological presentation of the dividing atrial shelf, which was partially formed by the wall of the left superior caval vein.