Complex connections, a young man presenting with shortness of breath, hypoxemia, right lumbar pain and left limb swelling

A 43-year-old Caucasian man was admitted to hospital due to shortness of breath, right lumbar pain and lower left limb swelling. Arterial blood gas sample showed mild hypoxemia and respiratory alkalosis. CT scan confirmed pulmonary embolism, splenic and bilateral renal ischemic lesions. Echocardiography showed right ventricular and coronary sinus (CS) dilatation. Using contrast echocardiography, a superior sinus venous atrial septal defect and persistent left superior vena cava (PLSVC) draining in CS were suspected. Cardiac CT confirmed the diagnosis and showed overriding right superior vena cava (RSVC) draining in both atria. The patient underwent successful surgical correctio