Reference values and correlates of right atrial volume in healthy adults by two‐dimensional echocardiography

Background Right atrial ( RA ) volume is an important parameter in the evaluation of patients with pulmonary hypertension. Aim of this study was to define reference ranges for RA volume by two‐dimensional echocardiography (2 DE ) in healthy adults. Methods A total of 596 healthy subjects [mean age 45.7 ± 14.6 years, range 18–88 years; 60.1% women] underwent a transthoracic echocardiography. In addition, a meta‐analysis was performed of published studies measuring RA volume in healthy subjects, using 2 DE single plane area‐length (A‐L) and/or method of disks ( MOD ) at end‐systole in apical four‐chamber view. Results In our cohort, RA volume was higher in men than women but did not vary with age. Body surface area ( BSA ), stroke volume ( SV ), and tricuspid annular plane systolic excursion ( TAPSE ) were the only independent variables associated with RA volume (β coefficient 0.569, 0.123, and 0.131, respectively; all P  < .001). In the pooled analysis, normalized RA volume was 25.7 ± 7.0 mL /m 2 in men and 21.2 ± 5.8 mL /m 2 in women for A‐L, 21.6 ± 5.6 mL /m 2 in men and 18.2 ± 5.4 mL /m 2 in women for MOD (all P values < .0001). The upper limit was about 36 mL /m 2 in men and 31 mL /m 2 in women for A‐L and 31 mL /m 2 in men and 27 mL/m 2 in women for MOD. Conclusions RA volume was found to be higher in men but not influenced by age. It was mainly correlated with larger BSA , indices of preload ( SV ) and RV longitudinal function ( TAPSE ). A statistically significant difference was found between A‐L and MOD .