Second, regarding the roles of inflammatory mediators and systemic inflammation, periodontal disease could cause a persistent inflammatory response or bacteremia, release inflammatory mediators such as C-reactive protein and interleukin-6, stimulate myocardial cell hypertrophy and apoptosis, promote myocardial fibrosis, and shorten the atrial effective refractory period, which could increase the occurrence risk and recurrence risk of atrial fibrillation [35]. This evidence concerns the gene IL6 and Myocardial fibrosis.