Been there, done that. Stress sure can bring it on -- I know from personal experience.
The good news is, assuming it is AFIB, it isn't really too serious. It just seems real serious when you are having an attack, thinking you are going to die. I've had it for about 15 years. Two pills a day keeps it in check most of the time. I still have one or two attacks a year.
For me, the biggest problem was getting it diagnosed. It would only occur every few weeks. By the time I'd get to the doctor's or the hospital, I'd be back to normal. The 24-hour Holter monitors never would catch it either.
Good luck. Give Ricki our regards.
Ken