Hi Angie, i hope you are feeling better. I get palpitations on and off sometimes they can last for a few minutes sometimes hours. I have in the past had them for a month which was constant and became a complete nightmare as i had been to the doctors and a&e many times. The palpitations were irregular and i was convinced there was something wrong with my heart even though id had ecg's on serveral occasions.
It was only when i accepted they part of the anxiety symptoms and although very frightening i slowly convinced myself it was normal to have them considering i had tottally stressed myself out about them and had become fixated about the whole thing.
I know propanalol helps abit as it slows the heartrate down alittle but at the end of the day its down to you to learn and relax as i found that was the answer. As soon as i learnt to relax they slowly dissapeared to my relief. I sometimes get them on the odd occasion but as long as you know they mean nothing they dissapear with relaxation.
ps i use relaxation tapes to help me unwind. I hope ive helped abit, best of luck, Chris.