I am 61 yrs okld (older than a lot of the ppl posting) but I am having rapid heartbeat as well. I have been to my doc and the ER a few times and they say nothing is wrong with me.  I do take migraine meds when I am having a headache and OTC sinus pills as well - I believe these are the cause of my rapid heartbeat.  Anyone else experience this when taking meds?  I try and just ignore it now since the ER and the doctors tell me nothing is wrong.