I did see this last year, which was the last time I checked my heart rate during
exercise, right before the brain surgery. My doctor at the time explained it was because of the CM1 and syrinx, which was affecting my blood pressure (because it was on the cerebellum)... I haven't checked my heart rate since because my blood pressure did drop dramatically after the surgery, enabling me to come off the medication, and I thought it was solved...
So help me. Please.