The presence of a PLSVC has various physiological and clinical implications.[3] The majority of the PLSVC drain into coronary sinus and only 0.03% of PLSVC drain into the left atrium in the absence of a coronary sinus or unroofed coronary sinus syndrome (UCSS)[4] or very rarely through the pulmonary vein.[5] The PLSVC draining into the left atrium is usually associated with a right to left shunt and carries the high risk of air or thromboembolism in to the systemic circulation and a great care should be taken to prevent it.[5] The exact type of UCSS in our case is not known, but since our patient was asymptomatic at presentation, we presume that this could be an incomplete type of UCSS. Isolated reports of double IJV or PLSVC draining into the right atrium or very rarely into the left atrium are available in literature, but these two uncommon findings are never reported in single patient.

Solanki SL, Divatia MJ, Gala K, Divatia JV. Central venous catheterization in a patient with double right internal jugular vein and persistent left-sided superior vena cava draining into the left atrium. Saudi J Anaesth. 2022 Apr-Jun;16(2):260-261. doi: 10.4103/sja.sja_5_22. Epub 2022 Mar 17. PMID: 35431755; PMCID: PMC9009556.