Frequent periodic leg movements during sleep in patients with restless legs syndrome (RLS) are associated with a greater progression of atrial fibrillation (AF) than in those with infrequent periodic limb movement disorder (PLMS). In a study published in PLoS One, the authors find this association is further strengthened by the observation that use of medications that reduce leg movements during sleep decreases the rate of progression in those with frequent PLMS. These findings are of potentially high clinical significance as recognition of another modifiable risk factor for AF progression—ie, frequent PLMS, especially in RLS patients—could help reduce the overall burden of AF in the elderly, a population with high prevalence of both RLS and AF. The study’s authors are Mahek Mirza, Win-Kuang Shen, Aamir Sofi, Canh Tran, Ahad Jahangir, Sulaiman Sultan, Uzma Khan, Maria Viqar, Chi Cho, and Arshad Jahangir.