The one I had was they used a local on my groin area and made a tiny incision, then inserted a very thin wire with a camera lens at the end to go up into my heart. It's scary but you don't feel anything. Only the entrance stings a little and they stitch you up when they are done. Then you get to see what the inside of your heart looks like. If it is a heart cath your getting.
I had one in May.They numbed the groin spot where they put the needle and gave me something in the oxygenline that relaxed me and made me drowsy but I was awake. They opened a heart artery and leg blockage.