Basically, this is just 110 cm of 7-French tubing with a balloon at the end. Simple as that. The whole point is: with the balloon, you can catheterize the right heart without fluoroscopy. Apparently Swan came up with it while watching sailboats; the correct term ought to be to “sail” the balloon into the pulmonary artery. Swan and Ganz used a 1.7mm (5Fr) PVC catheter with only two lumens (one for the balloon). They inserted it via a cut-down vein in the cubital fossa. After 40 or so dog experiments, they moved on to trial it in 60 humans, with encouraging results. The number of disastrous complications was comparable with the standard of the time (i.e. although in at least one dead patient their catheter was directly implicated as the cause of multiple pulmonary emboli, it was excused because thrombotic complications were par for the course in such patients).
Anyway. Here is a map of the catheter an its various lumens:
Here is a picture of an actual decommissioned catheter: