The last day my heart have started to beat heavily quite randomly.

Its not beating faster or anything its just pumps with more force. Dont know how to describe it. No pain or anything but its quite disturbing.

Any ideas about this? My aunt who works with hearts all day at the clinic told me it was nothing to worry about when I had this a couple of years ago. Never had it since but now its back and a bit worse as it keeps doing it. Its just a few pumps that feels harder then its back to normal. But it keeps doing this for the last 24 hours ( a few heavy beats every hour)

Will try and get hold of my aunt when she gets back but thought I would ask the PF lot if someone else had this?