I just had one today.
I had to get clearance for the upcoming surgery for my shoulder. I had a EKG done a couple weeks ago and they said something was different (whatever that means) from the last EKG 6 years ago.
Today they did an ultrasound then I had to do the treadmill and immediately after another Ultrasound. The only problem was they thought the treadmill should take 7 minutes max to get my heartbeat up to the 147 range but it took 12 minutes and 2 more increases in speed and elevation. lol In the end they said all looks Good, no anomalies, no blockage, no irregularities. The only thing wa my blood pressure was a little high. Normally after work (12 hr shift) if I get it tested it's around 140 / 90. Today it was 161/104, just a little high, not sure why. After all the test though they were not to concerned. I will get the final report in a week or so from the cardiologist.
Honestly after reading on this a little and doing it I think it's something anyone over 40 should have done. It would help catch a lot of pre heart attach victims since it shows the heart valves working and how the heart works under stress.