Rozenbaum Z, et al. - In this single-centre retrospective study, researchers focused on the link between small left atria (LA) and outcome in a relatively large heterogeneous population of hospitalized patients. Participants were 17,343 inpatients with an echocardiographic assessment and an available left atrial volume index (LAVI) measurement, 288 with small LA (LAVI <16 mL/m²), 7531 patients had LAVI within normal limits (16–34 mL/m²) divided into low normal (16–24.9 mL/m²; n = 2636) and high normal (25–34 mL/m²; n = 4895), 4720 patients had large LAVI (34.1–45 mL/m²) and 4804 had very large LAVI (>45 mL/m²). During median follow-up of 2.4 years, a higher risk for in-hospital mortality and all-cause mortality was reported for small LA vs high normal LA after adjustments for age, gender, and baseline characteristics with a P-value <0.2 in univariable analyses. For in-hospital and long-term all-cause mortality, an increase in the risk by 10% and 8%, respectively, was observed for every mL/m² decrease below high normal LA size. LA volume should be referred to as J-shaped in terms of mortality.