My suggestion is to write down all your questions and concerns.
Make an appointment with your cardiologist. Bring your notes and get the correct answers.
I would be doing you a great disservice by citing general articles which both of us would find on the internet.
Your cardiologist knows your medical history, the extent of your condition and can best prepare you for what to expect during and following the catherterization procedure.
You will be in my thoughts and prayers,