There's a difference...
Holding area is where the prep/recovery is done. You have plenty experience working there if you've pulled many sheaths in your career. For an outpt lab, you admit them, start an iv, draw labs, do an ekg, shave/prep the area, and then send them off.
Then for recovery, you monitor their access site and/or pull the sheath(s). You monitor their vitals as they are fresh from conscious sedation. You have to be prepared for an occasional emergency, such as a vasovagal response, closure failure, or even mental status changes. We do give them plenty of anticoagulants after all...then you do the discharge teaching and send them home.
The cath lab is where the real fun and action is at... I am fortunate that I was allowed in with my limited ICU experience of 5 years. Yes, 5 years! Most of the nurses had 15-20. It is very intense, and you must be very comfortable with gtts, IABPs, multi-tasking, assessment skills, and you MUST have the ability to anticipate! 1 year of ICU will not get you into any lab that I know, but if you work in holding then you've got a chance to cross-train in the lab.
In my lab, we rotate through holding area. Bleh. It's boring. But it can be really, really busy! But I prefer the action of the lab.