A catheter for insertion into the right atrium from the right subclavian vein has an elongate flexible shaft having a proximal portion and a distal portion. The distal portion has a preformed shape including a first arc portion having a curvature of from about 20 degrees to about 50 degrees relative to the proximal portion and a second arc portion extending distally from the first arc and having a curvature of from about 135 to about 200 degrees relative to the first portion. The first arc has an arc radius of from about 6 inches to about 10 inches and the second arc has an arc radius of from about 1 to about 2 inches. The catheter terminates in a generally straight terminal portion extending distally from the preformed shape.
