I am not familiar with cardiology but yes I agree that it depends on the tests they run. WIth a whole panel of tests they might take longer, and there is a variety of tests, blood that needs to be sent to a lab, monitor that you have to wear throughout the day{s} and they need to read it and that takes time. They could run a stress test or an echo, and then more invasive tests if needed

I would call back the office and ask them what they're going to do, they should tell you the procedures and everything