I have been getting this "feeling for about 3 months. i can only explain it like this.
i get a really strong heartbeat for about what i feel is about 10 beats and the a strange feeling of euphoria after like an adrenalin rush wave after wave. has anyone else experienced this?? it happens maybe once a week.
i got that a few weeks ago, nearly every day whenever i layed down, also had a sort of tight feeling across my chest...didnt get the euphoria bit though!
Are you on any medication cos certain sleeping tablets or antidepressants can cause palpitations, which is what it seems like you are suffering from. I experienced this when I was taking amitriptyline a couple of years ago. Although it is quite scary I don't think its anything to worry about. When this happens try lying down for a few minutes til it passes.