Rooney MR, Soliman EZ, Lutsey PL, et al. - In this cross-sectional study utilizing visit 6 (2016–2017) data from the community-based multicenter observational ARIC study (Atherosclerosis Risk in Communities), researchers investigated how prevalent subclinical atrial fibrillation (AF) is in a community-based elderly population. They also characterized subclinical AF and determined whether 4 vs 2 weeks of continuous ECG monitoring offers an incremental diagnostic yield. They reported a prevalence of 2.5%, which was lower than earlier reported. Among white men, white women, black men, and black women, the estimated prevalence was 3.3%, 2.5%, 2.1%, and 1.6%, respectively. In most cases, subclinical AF was intermittent (75%). A substantial incremental diagnostic yield was offered by monitoring beyond 2 weeks.