Age-, body size-, and sex-specific reference values for right ventricular volumes and ejection fraction by three-dimensional echocardiography: A multicenter echocardiographic study in 507 healthy volunteers

Background-Right ventricular (RV) volumes and ejection fraction (EF) vary significantly with demographic and anthropometric factors and are associated with poor prognosis in several cardiovascular diseases. This multicenter study was designed to (1) establish the reference values for RV volumes and EF using transthoracic three-dimensional (3D) echocardiography; (2) investigate the influence of age, sex, and body size on RV anatomy; (3) develop normative equations. Methods and Results-RV volumes (end-diastolic volume and end-systolic volume), stroke volume, and EF were measured by 3D echocardiography in 540 healthy adult volunteers, prospectively enrolled, evenly distributed across age and sex. The relation of age, sex, and body size parameters was investigated using bivariate and multiple linear regression. Analysis was feasible in 507 (94%) subjects (260 women; age, 45±16 years; range, 18-90). Age, sex, height, and weight significantly influenced RV volumes and EF. Sex effect was significant (P<0.01), with RV volumes larger and EF smaller in men than in women. Older age was associated with lower volumes (end-diastolic volume, -5 mLdecade; end-systolic volume, -3 mL/decade; EF, -2 mL/decade) and higher EF (+1% per decade). Inclusion of body size parameters in the statistical models resulted in improved overall explained variance for volumes (end-diastolic volume, R2=0.43; end-systolic volume, R2=0.35; stroke volume, R2=0.30), while EF was unaffected. Ratiometric and allometric indexing for age, sex, and body size resulted in no significant residual correlation between RV measures and height or weight. Conclusions-The presented normative ranges and equations could help standardize the 3D echocardiography assessment of RV volumes and function in clinical practice, considering the effects of age, sex, and body size.