I had it done and while my heart raced and the pulse rate got up to about 145 my blood pressure did not raise all that much. I will not say it was easy but it is not at all as bad as I thought it was going to be. I guess the worse part is when they jam the untrssound wand into your ribs, that is uncomfortible.
Luckly, when you get any stress test done, you tend to have many trained nurses and a cardiologist with you and if they see anything unsafe or strange, they will end the test immediately.
Good Luck with your test! :)