I feel a little tickle inside my chest sometimes any ideas?

So a little back story I'm 27, i have a history if heart palpitations, i also experienced an episode of afib at the age of 23 directly caused by vomiting, and again 2 years later caused by the same thing, I've had numerous tests done to rule out any heart defects such as ekg, echocardiogram, a lot of blood work, and monitor. I was told my heart is fine. So obviously i do have an electrical issue within my heart, but the doctors aren't concerned about it because i am asymptomatic, no fainting, chest pains, dizziness etc. But sometimes i can feel a very slight tickle in my chest, and this can go on for about a hour or so at a time, i can't say its my heart because i can't really be sure, but i also have chronic acid reflux which may be to blame, but i thought I'd post on here not for a diagbosis but simply to see if maybe you have felt the same thing and maybe you figured out what it was. By the way heart palpitations run deep in my family but has never caused any problems for anyone so i don't feel like I'm in trouble or anything I'm just rather curious.