This has been happening to me off and on since last summer. I can really feel my heart beating in my chest and feel slightly short of breath - like I need to take a deep breath in but can’t. This can go on for a few hours. I can still carry on as normal but it’s quite annoying.
I’m 48 and otherwise perfectly fine and quite fit.
I assume if it was anything too serious I’d be dead/ill by now as I’ve been having this for 10 months or more now.