The old thinking had obesity only indirectly involved with atrial fibrillation. That is, fatness perpetuated AF because the extra weight led to other conditions like high blood pressure, diabetes and sleep disorders.
Emerging data paint a gloomier a picture for patients with high body fat composition. It looks like fatness itself has direct and negative effects on the atria.
I just posted about the clinical problem of obesity in AF and two new trials that offer immediately usable information. (Remember what the best tool for treating AF is.)
The link for the Trials and Fibrillation post is: Obesity and Atrial Fibrillation–New information for the whiteboard.