well i can honestly say i totally identify, this is why i dont do long esters anymore, after 4-5 weeks i get fucked heart beat terrible palpitations at night that keep me awake. Last time i was on fina testoviron i had that as u explained very fast heart beat then i have had ekg and tests and all they could tell me was my hear beat was irregular. One of the functions was not quite normal, problem is i read up on all heart diseases and seems like i had some similar symtom of every one, are you using t3 at all? or clen? the thing i came accross which seemed most like what i had is called mitral valve prolapse, it explains the fast heart beats and then other things about it, it can be related to thyroid problems also, thats all i can suggest, thing is i havent really juiced for a while and i havent had a single problem!

peace