I've had the exact same issue a couple of years ago during a routine class 1 renewal. My pulse racing away at the doctor lead to a ECG-test which stated I had "sinus tachycardia". It was investigated by the CAA, they ran some tests and I got my medical renewed when they where 100 % it was only due to "white coat syndrome". A few tests to go trough (some samples, 24 hour ECG), but nothing serious. Just relax and you'll be fine!
