The extent of NLRP3 inflammasome activation in atrial whole-tissue lysates and cardiomyocytes from patients with paroxysmal AF or long-term persistent AF was assessed by immunoblotting. A mouse model of NLRP3-specific activation in cardiomyocytes was developed. In vivo electrophysiology was used to assess atrial arrhythmia vulnerability. Here, NLRP3 is linked to Paroxysmal atrial fibrillation.