Persistent left superior vena cava complicating hemodynamic monitoring catheterization.

Two cases of flow-directed, balloon-tipped catheterizations of the right heart via a persistent left superior vena cava are presented. In both cases, the monitoring catheters assumed similar, atypical configurations on plain chest roentgenograms. Recognition of the characteristic configuration of the course of transvenous catheters through the persistent left superior vena cava allows for plain film diagnosis of this anomaly.