Right atrial size and function assessed with three-dimensional and speckle-tracking echocardiography in 200 healthy volunteers

AIMS: Right atrial (RA) size predicts the outcome in some pathological conditions but reference values for RA volumes and myocardial function remain to be defined. Thus, we used two-dimensional speckle-tracking echocardiography (2D-STE) and three-dimensional echocardiography (3DE) to define normative reference values of RA volumes and function. METHODS AND RESULTS: Two hundreds healthy volunteers (43 ± 15 years, range 18-75; 44% men) underwent two-dimensional echocardiography (2DE) to obtain RA volumes and longitudinal strain (LS) of RA wall using 2D-STE, and 3DE to measure maximal (Vmax), minimal, and preA volumes to calculate total, passive, and active emptying volumes (TotEV, PassEV, and ActEV) and emptying fractions (TotEF, PassEF, and ActEF). Three-dimensional echocardiography volumes (Vmax, 52 ± 15 mL vs. 41 ± 14 mL), EVs (TotEV, 33 ± 10 mL vs. 24 ± 9 mL), and EFs (TotEF, 63 ± 9 vs. 58 ± 9%) were larger than 2DE ones (all P < 0.0001). Indexed 3D volumes were significantly larger in men than in women. RA TotEF correlated with total LS (r = 0.24, P = 0.025) and PassEF with positive LS (LSpos; r = 0.34, P < 0.0001). Ageing was associated with a decrease in passive (LSpos, r = -041; PassEV, r = -0.26; PassEF, r = -0.38; all P < 0.0001) and an increase in active RA function (negative LS, r = 0.34; ActEV, r = 0.25; all P < 0.0001; and ActEF, r = 0.15; P = 0.035) in order to maintain TotEV (r = -0.14, P = 0.05). CONCLUSION: Our study provides normative values for RA volumes and function measured by 3DE and 2D-STE in a relatively large cohort of healthy subjects with a wide age range. These data will help clinicians to identify RA remodelling and dysfunction.