NLRP3 and obesity due to melanocortin 4 receptor deficiency: Activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome is increased in patients with paroxysmal and long-standing-persistent AF (86), patients that go on to develop post-operative AF (87), and patients with risk factors for AF such as diabetes and obesity (88, 89) via both priming (increased expression of components of the NLRP3 inflammasome) and triggering (assembly of the NLRP3 complex) mechanisms.