I had it! I was having weird stuff with my heart rate, and I wasnt stable enough to get up on the tread mill. They laid me on my left side, put in the meds, and my heart rate sped to 145 to 150. It felt a bit like the early stages of an anxiety attack. They got their reading, and then placed me back under that machine that whirls around you. When that was done, they gave me some anti anxiety meds, and let me rest for an hour. then the hubby took me home. easy breezy.