Misdiagnosis of persistent left superior vena cava with unroofed coronary sinus as a coronary sinus-type atrial septal defect.

KEY CLINICAL MESSAGE: Awareness of persistent left superior vena cava (PLSVC) with unroofed coronary sinus is crucial. Pre- and perioperative evaluation of this association is necessary for surgical plan. Creating an intra-atrial tunnel to divert LSVC to right atrium without obstructing the mitral valve or the pulmonary veins is the safe surgical approach.

ABSTRACT: Unroofed coronary sinus syndrome is a rare congenital heart defect representing less than 1% of all atrial septal defect (ASD) types, and may be associated with persistent left superior vena cava (PLSVC) which may be missed during preoperative diagnosis. Herein, we present a case of a 2-year-old patient who underwent an operation for repair of a coronary sinus-type ASD; however, PLSVC was detected intraoperatively. An antra-atrial tunnel has created to divert the flow of PLSVC into the right atrium along with the repair of the ASD.