[[Unusual course of a pulmonary artery catheter through a persistent superior vena cava] ].

We report the unusual course of a pulmonary artery catheter through a persistent left-sided superior vena cava. After left subclavian vein cannulation and downward left-sided paramediastinum course, the Swan-Ganz catheter enters the right pulmonary artery. Haemodynamic monitoring was consistent with the diagnosis of septic shock developed by this 56-year-old woman, after cephalic duodenopancreatectomy. Persistent left-sided superior vena cava occurs in 0.5% of the population and 5-10% of patients with congenital heart diseases. It drains into the right atrium through the coronary sinus in 92% of cases and is associated with an absent right superior vena cava in 20% of cases. The left-sided superior vena cava persists when the caudal part of the left anterior cardinal vein does not degenerate. A persistent left superior vena cava may be medically relevant during implantation of pacemaker leads or radiofrequency ablation, during cardiac surgery for placement of a retrograde coronary sinus cardioplegia catheter and during transjugular intrahepatic portosystemic shunt placement.