Has anyone else had AFIB after their MCAS symptoms started?

2 years ago I was healthy with no major problems then one day out of nowhere my MCAS symptoms started, about a month after that my heart went haywire and I was diagnosed with afib. I’ve seen 4 cardiologists and none of them have a clue why an in shape 25 year old would just go into afib. I’m just throwing this out there to see if anyone else with MCAS also has afib.