I am a nurse and I think with our medical knowledge it does make you look at things more closely. I have tachycardia, and have been told (when it was up to 160 in the ER once, that it was sinus tachycardia). But, I still have this happening to me and I still can get scared. One doctor thought I had an svt, so that is always in the back of my mind and a worry. This was never documented though, all the EKG's I've had has been sinus tachycardia. I had a 24 hour holter monitor done, which I did have a couple of episodes on, so I am still waiting for the results. The waiting is making me very nervous. But in answer to your question, I think having a medical background does make it worse because you know more things about what to worry about.