@mjohns Least costly is going to be Kardia L6 and you can skip the paid subscription if you wish, but the paid subscription, even for a month, will give you more data. Most costly would be a decent smart watch or smart ring. I wear a Galaxy 4 at the moment that was updated to read blood pressure, ECG and AF detection, and of course O2 saturation during sleep. They're not cheap, but they probably won't make your banker groan either. They all do a good job detecting irregular patterns in your rhythm, but not always spotting actual AF. Sometimes they're unable to say definitively yes or no, so they say something like 'indeterminate, please see your family doctor.'

My Galaxy watches, a 4 and newer 6, both do a pretty good job, though, and my electrophysiologist accepted my 4's graphic representation of my ECG when I was in AF at face value. Didn't want to see me, didn't need a proper ECG. He took one look and said that I was obviously back in AF and that he'd schedule another ablation....which worked.