Small cardiac vein draining into the inferior vena cava.

Cardiac venous anomalies are rare congenital anatomical anomalies, which are most commonly found on computed tomography scans as an accidental finding. We report a case of a 14-year-old child who was operated for an atrial septal defect, and during the operation, we came across an anomalous drainage of the small cardiac vein into the inferior vena cava. The child's postoperative course was uneventful.