@pbd67 I can't say definitively, but the Vagal response or tone is well established as a factor in some cases of AF. GERD and stomach distension are known triggers, as are electrolytic defects. So, it's entirely conceivable that the GLP-1 has acted as a trigger. Did it 'start' or bring on your AF? Almost certainly not; your AF was waiting for an excuse, and it came. Neither of us can prove it, but if you were to cease the GLP-1 and never had another round of AF, that might be a great clue. If you do that, and then try GLP-1 for a couple of doses, and you get the AF, that would be strong proof that it is a trigger...but your AF is still 'there'. This is my opinion...for what it's worth.