[Persistent left-sided superior vena cava diagnosed after flow-directed pulmonary artery catheterization; report of a case].

We describe a case of persistent left-sided superior vena cava discovered after insertion of a pulmonary artery (PA) catheter. The diagnosis was suggested by chest X-ray after PA catheter placement and was subsequently confirmed by an echocardiograph. A 68-year-old man was admitted to our ICU because of septic shock induced by MRSA enterocolitis. In order to monitor the hemodynamic state of the patient, a PA catheter was inserted through the left subclavian vein after placement of a central venous and flexible double lumen catheters through the right internal jugular and subclavian veins, respectively. A chest X-ray showed the PA catheter passing along the left border of the heart. An echocardiograph showed the PA catheter passing through the coronary sinus into the pulmonary artery. Anesthesiologists and intensivists should be aware of the occurrence of left-sided superior vena cava in order not to mistake catheters placed in it as being in the arterial circulation or malpositioned outside of the venous circulation.