I haven't seen any convincing evidence that caffeine is going to be a trigger for people. In fact, the evidence is that caffeine enhances heart function, although not six cups of it a day, or a single Mountain Dew. It wasn't caffeine that set me off...if was being in the middle of a mid-morning run. I still have a light-caffeine pot of tea each morning to start hydrating, and then have a pretty decent sized coffee, full test, mid-afternoon with the missus. My heart rate does increase, but it doesn't come close to setting off PACs or AF.

With that comment aside, I do support a methodical exploration of what could be one's triggers, and that would clearly have to include trials of caffeine-free and caffeine-loading days, probably two or three days apart as a minimum to clear out all residues and to let the heart stabilize. Also would be tests for magnesium supplementation, calcium, and potassium supplementation, exercise, the kinds of foods that reliably disagree with the person, etc. If the AF seems to be only loosely associated, or not at all, then it's something other than what you're trialing.