Once for my lungs, and once for my heart... Turned out all that was 'just fine' at that time.
Of course, it's NORMAL to be antsy about such things. Me? I just cannot sleep the nite before and come into the place like a zombie! I mean? How much BAAD late nite TV can you find on cable? HEAPS!
Mostly for such tests they either put you out under a mild anathestic or what they call a 'twilight' anathestic. Either way? Once you're out? You won't care! Once you come to, you'll be given instructions. I suggest you follow these to the letter, please! Then? You'll get results when they say. Waiting at times, is horrid? But WAIT you must. Sometimes if you are nice, and polite w/heaps of pleases and thank-yous? Techs mite give you a hint that it's nothing to worry about? Others won't give you the time of day...so don't expect immediate answers.
Consider it just one of those 'things' we have to endure to find out what all is going on! 's and A good experience tomorrow too! - j