Are there any studies about HOW covid causes irregular heartbeats?

Like many of you, and many at the subreddit r/covidlonghaulers  , I suffer from daily heart palpitations in the form of PVC's and PAC's. It started after a mild COVID infection and never went away.

I see so many people write the exact same story, yet nobody has any answers as to how and why.

So, if you know anything please share your knowledge. Thanks.