Resting hr usually 78 at pcp. today driving it was 105.fairly anxious. not dehydrated.passed stress test.what would cause this increase for over 1 hr?

Anxiety: Likely caused your elevated heart rate. If this happened while you were driving that is not too unusual in today world. Normal heart rate is between 60-100, so you were just a little elevated. Since you passed a stress test and this is just a little elevated, I would not be concerned. It sounds like a normal stress reaction. If worried about it fu with PCP.