I am a 23/Male recently diagnosed with GERD. Just for precautionary
reasons, I had an Upper Endoscopy done in which my stomach checked out
A-OK. The Gastroenterologist was concerned, however about my heart
rate. My resting heart rate usually runs in the low 90's. Before the
procedure, I was very nervous and actually for a short time had a
heart rate approaching 140. During the procedure my heart rate calmed
down a little bit but even after having 12 mg of Versed and 150 mg of
Demerol given intravenously the HR remained in the 110's until after
the procedure at which time it eventually came back to the normal low
90's. I have had thyroid tests done which came out with normal
results. I am only on one medication, (Protonix) for the GERD.

Should I be concerned about my heart rate being abnormally high while
under sedation? What sort of conditions could this possibly be a sign
of? What sort of tests would facilitate the diagnosis if it is of
concern?

First I'd be concerned about a resting rate in the 90s.