can anyone give me some feedback? i am a 19 year old female 5ft 10inch my weight is currently 8 stone, i dont smoke or drink alcohol i dont take anything containing caffeine! for the last 4 years i have had a rapid heartbeat it speeds up when i stand up and move about it can reach beats of 160bpm but usually is around 120 im on propranonol betablockers iv had ecgs blood tests docs say its anxiety stress etc but im beginnin to wonder why im fine when im sat down or lay but as soon as i get up and about it shoots right up has anyone got any answers please thanks kim x