Thank you erijon, alleycat2 and ed34 for posting a reply. I will tell my Dad what I have learned. I feel for my own sanity I will also talk to the heart Dr. to make sure he or someone as reputable is in the room with my Dad when they do this test.
Thanks again for the information. It helped tremendously.
With blood pressure being constantly monitored, and ekg wired up and your Father being continually asked how he feels, it is quite safe. As already said, there will be cardiologists at shouting distance. When they have concerns about the patients health during the procedure they inject the drug more slowly, so there isn't a big impact. This also gives them much more control over the whole situation. I had one in feb this year and it was much gentler than my previous one in 2007. They injected the drug very quickly then and I remember suddenly gasping for air and going into panic mode. The recent stress test had a specialist continually asking me how I was feeling. At the end of the test, I just had to lay flat for about 20 minutes but the effects wore off very quickly, after about 3-5 minutes.
I have had this test many years ago and it was frightening and horriable. Ihad it again a month ago and it was no problem. They have greatly improved the chemical they use now. The cardilogist is indeed present and the can stop instantly. I personally think stress tests are a waste of time. I put more faith in the test where they inject a necular item then put you in a clamshell and record your heart process.
Keep in mind that these tests are conducted with a cardiologist either in the lab or in very close proximity. I have had this type of stress test and the injection causes and immediate increase in heart rate and can be stopped immediately. I'm sure given your father's condition the cardiologist will be very involved. If they see anything that looks out of normal ranges they will stop the test immediately and the effects of the drug can be stopped like turning off a light switch.
Hope this helps,
Jon