Actually when I had my open heart bypass surgery, they stopped my heart for about 6-8 hours. Then restarted it after they were done. Afterwards I had problems with my memory, still do, then 3 months later the T started.
I had a talk with a psychiatrist about my memory, he told me even though my brain was still getting blood and oxygen to it, there are things not understood that affect the brain under those conditions. He also said it may take a few years for my memory to get back to where it was. I asked him if this could have caused my T, he said absolutely, after having my brain traumatized in that manner....