Is there a common description of heart palpitations? could they be consistent with regular twitching in the upper left side of the chest?

Palp: I have many different descriptions...The only description i can give from personal experience is a hard pounding that feels slow (random occurrence) or a light fluttering that feels fast (often when i lay on left side).... I have never had an ekg, echo, or any other heart eval though. I am the doc here just describing personal experience. Too much caffeine.