Stress Test and Ultrasound? Help?

Ok so I'm having some funky stuff happen with my heart. My heart rate has been running low and for the last two days I've been suffering from chest pains.
So cardio doc wants to perform an ultrsound and stress test via treadmil in the morning! I am scared to death! I'm scared of overdoing it as he wants to get my heart rate up pretty high. I'm scared of what he may find (blocked arteries, ect..) and if it makes my symptoms worse! Has anyone had this done? Please send me some good vibes and tell me your stories!

I had stress test and echo cardigarm back in 2007. But mine was due to fast heart rate and PVcs. Pvcs are extra heart beats that feels likes your heart stops. (not fun at all when you are having them like every five heart beats). The stress didn't take any time at all to do. It wasn't hard and I think I was only on treadmill for maybe five minutes and all I did was walk. The echo or ulrasound was no problem at all. Also I did this one test were they eject so stuff into my vein and I laid on a table while this big machine took pics of my heart. Of course this test took longer because it has to have so many regular heart beats and I kept having pvcs. It turns out everything is fine and the pvcs are beign. I just take a beta blocker everyday and stay away from caffeine n diet pills n different things Like that.

I hope everything turns out ok and don't worry you will not over do it cause stress test are not hard to do. Good luck