HAVCR2 and Paroxysmal atrial fibrillation: In this study, the proportion of Tim-3 + cells in peripheral blood of patients with paroxysmal and chronic AF was significantly decreased, and the level of Tim-3 + cells in peripheral blood of patients with chronic AF was lower than that of patients with paroxysmal AF, indicating that Tim-3 + cell population is also involved in the pathological progression of AF and is closely related to AF, which may be a therapeutic target for the improvement of AF.