I have had two stress tests of the formal kind at the Cardiologist a few years ago. I signed a form acknowledging that if my heart quit and they cannot resuscitate etc I will be dead and that's that. Its a risk of the test itself. One was a treadmill for 12 minutes with a target heart rate of 150+ and it WILL induce a failure in your system soon enough before 12 minutes when your medical issues in respitory and other systems fail the load requirements as you walk towards your death uphill.
My second test was two years ago it took into account that I had a hip replacement and is not able to walk more than 300 yards at once without the nerves in the spine failing at one leg or both. (Both diagnosis confirmed in addition to others) They used a chemical via IV to expand the heart blood vessals to the MAX OPENED in diameter. Forcing the heart to redline and move volume. If you have the volume to do it you will be fine. IF your blood pressure fell too much out you go if not dead once the heart stops then and there.
If you do not have the reserve volume to meet the stress emergency imposed onto your body... this happens... The third lift is classic for reserve volume blood failure at the heart under load. Out you go.
They had staff and ambulance standing by with cardiac support with the hospital not too far down the street for both of those tests. I failed one and showed symptoms of my known medical issues in the other. Technically both were a failure.
I spent my life lifting 120 pound boxes of meat, seafood and produce etc from the trailer floor to the ceiling twice daily and sometimes to small wood from big wood behind the trailer in the warehouse dock among other very physical jobs. In those days I was perfect in fighting trim, weight and can fight above my weight class taking on bigger people than me.
Fast forward to now. Forget all that. The medical situation asserted itself. And that's where I am. As joints fail and they chop out and drop in new metal into my body I gain weight lifting restricting for that limb. So even if I wanted to move that 110 pound bag of horse feed taller than I am across the farm its not going to happen it will kill me. So in some ways Im out of it.