I have been both very relaxed with a nice slow even heart beat and also very agitated with a wildly pounding heart beat when on shrooms. I found that both of those states related directly to my emotional state at the time. As for the actual physiological effects of shrooms on the body, all I think I know is that psilocybin mimics serotonin, the neurotransmitter in the brain and it migrates to lesser travelled neurological pathways. this can create some tension an emotional distress as you are coming up as you are faced with areas of yourself or the world around you that you rarely if ever consciously see. I suppose this loud lead to an elevated heart rate and higher blood pressure.
