[10], [11] In addition a high CRP level was associated with an abnormal left atrial substrate and a high incidence of nonpulmonary vein AF sources. [12] Moreover, one recent study has shown a relationship between local atrial inflammation and the type of AF. [13] Aside from inflammation-linked effects, CRP plays a critical role in immunity pathways, and the presence of CRP induces important phenotypic changes in the vascular endothelium, including apoptosis [14] and has direct toxic effects on endothelial cells which are mediated via reactive oxidant species. [15]. Here, CRP is linked to atrial fibrillation.