Left Ventricular Diastolic Function in Healthy Adult Individuals: Results of the World Alliance Societies of Echocardiography Normal Values Study

Background: The World Alliance Societies of Echocardiography (WASE) study was conducted to describe echocardiographic normal values in adults and to compare races and nationalities using a uniform acquisition and measurement protocol. This report focuses on left ventricular (LV) diastolic function.Methods: WASE is an international, cross-sectional study. Participants were enrolled with equal distribution according to age and gender. Echocardiograms were analyzed in a core laboratory based on the latest American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. Left ventricular diastolic function was assessed by E, E/A, e' velocities, E/e', left atrial volume index (LAVI), and tricuspid regurgitation velocity. Determination of LV diastolic function was made using the algorithm proposed by the guidelines.Results: A total of 2,008 subjects from 15 countries were enrolled. The majority were of white or Asian race (42.8%, 41.8%, respectively). E and E/e' were higher in female patients, while LAVI was similar in both genders. Consistent increase in E/e' and decrease in E/A, E, and e' were found as age increased. The upper limit of normal for LAVI was higher in WASE compared with the guidelines. The lower limits of normal for e' were smaller in elder groups than those in the guidelines, while the upper limits of normal for E/e' were below the guideline values. These findings suggest that the cutoff value for LAVI should be shifted upward and age-specific cutoff values for e' should be considered. In WASE, <93.6% of patients were classified as normal LV diastolic function using the guidelines' algorithm, and the proportion increased to 97.4% when applying the revised cutoff values for LAVI obtained in our study.Conclusions: Guideline-recommended normal values for e' velocities and LAVI should be reconsidered. The algorithm for the determination of LV diastolic function proposed by the guidelines is useful, but adjustments to LAVI could further improve it

Normal Values of Three-Dimensional Right Ventricular Size and Function Measurements: Results of the World Alliance Societies of Echocardiography Study

Background: Normal values for three-dimensional (3D) right ventricular (RV) size and function are not well established, as they originate from small studies that involved predominantly white North American and European populations, did not use RV-focused views, and relied on older 3D RV analysis software. The World Alliance Societies of Echocardiography study was designed to generate reference ranges for normal subjects around the world. The aim of this study was to assess the worldwide capability of 3D imaging of the right ventricle and report size and function measurements, including their dependency on age, sex, and ethnicity. Methods: Healthy subjects free of cardiac, pulmonary, and renal disease were prospectively enrolled at 19 centers in 15 countries, representing six continents. Three-dimensional wide-angle RV data sets were obtained and analyzed using dedicated RV software (TomTec) to measure end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction (EF). Results were categorized by sex, age (18-40, 41-65, and >65 years) and ethnicity. Results: Of the 2,007 subjects with attempted 3D RV acquisitions, 1,051 had adequate image quality for confi-dent measurements. Upper and lower limits for body surface area-indexed EDV, ESV, and EF were 48 and 95 mL/m2, 19 and 43 mL/m2, and 44% and 58%, respectively, for men and 42 and 81 mL/m2, 16 and 36 mL/m2, and 46% and 61%, respectively, for women. Men had significantly larger EDVs, ESVs, and stroke volumes (even after body surface area indexing) and lower EFs than women (P < .05). EDV and ESV did not show any meaningful differences among age groups. Three-dimensional RV volumes were smallest in Asians. Conclusions: Reliability of 3D RV acquisition is low worldwide, underscoring the importance of future improve-ments in imaging techniques. Sex and race must be taken into consideration in the assessment of both RV volumes and EF. (J Am Soc Echocardiogr 2023;36:858-66.

Normal Values of Cardiac Output and Stroke Volume According to Measurement Technique, Age, Sex, and Ethnicity: Results of the World Alliance of Societies of Echocardiography Study

Background: Assessment of cardiac output (CO) and stroke volume (SV) is essential to understand cardiac function and hemodynamics. These parameters can be examined using three echocardiographic techniques (pulsed-wave Doppler, two-dimensional [2D], and three-dimensional [3D]). Whether these methods can be used interchangeably is unclear. The influence of age, sex, and ethnicity on CO and SV has also not been examined in depth. In this report from the World Alliance of Societies of Echocardiography Normal Values Study, the authors compare CO and SV in healthy adults according to age, sex, ethnicity, and measurement techniques. Methods: A total of 1,450 adult subjects (53% men) free of heart, lung, and kidney disease were prospectively enrolled in 15 countries, with even distributions among age groups and sex. Subjects were divided into three age groups (young, 18-40 years; middle aged, 41-65 years; and old, >65 years) and three main racial groups (whites, blacks, and Asians). CO and SV were indexed (cardiac index [CI] and SV index [SVI], respectively) to body surface area and height and measured using three echocardiographic methods: Doppler, 2D, and 3D. Images were analyzed at two core laboratories (one each for 2D and 3D). Results: CI and SVI were significantly lower by 2D compared with both Doppler and 3D methods in both sexes. SVI was significantly lower in women than men by all three methods, while CI differed only by 2D. SVI decreased with aging by all three techniques, whereas CI declined only with 2D and 3D. CO and SV were smallest in Asians and largest in whites, and the differences persisted after normalization for body surface area. Conclusions: The present results provide normal reference values for CO and SV, which differ by age, sex, and race. Furthermore, CI and SVI measurements by the different echocardiographic techniques are not interchangeable. All these factors need to be taken into account when evaluating cardiac function and hemodynamics in individual patients. (J Am Soc Echocardiogr 2021;34:1077-85.

Normal Values of Left Atrial Size and Function and the Impact of Age: Results of the World Alliance Societies of Echocardiography Study

Background: Left atrial (LA) evaluation includes volumetric and functional parameters with an abundance of diagnostic and prognostic implications. Solid normal reference ranges are compulsory for accurate interpretation in individual patients, but previous studies have yielded mixed conclusions regarding the effects of age, sex, and/or race. The present report from the World Alliance Societies of Echocardiography study focuses on two-dimensional (2D) and three-dimensional (3D) measures of LA structure and function, with subgroup analysis by age, sex, and race. Methods: Transthoracic 2D and 3D echocardiographic images were obtained in 1,765 healthy individuals (901 men, 864 women) evenly distributed among age subgroups: 18 to 40 years (n = 745), 41 to 65 years (n = 618), and >65 years (n = 402); the racial distribution was 38.4% white, 39.9% Asian, and 9.7% black. Images were analyzed using dedicated LA analysis software to measure LA volumes and phasic function from 3D volume and 2D strain curves. Results: Three-dimensional maximum and minimum LA volumes adjusted for body surface area were nearly identical for men and women, but women demonstrated higher 3D total and passive emptying fractions (EFs). Two-dimensional reservoir strain was similar for both sexes. Age was associated with an incremental rise in LA volumes alongside characteristic shifts in functional indices. Total 2D EF and reservoir and conduit strain varied inversely with age, counteracted by higher booster strain, with a greater magnitude of effect in women. Active 3D EF was significantly higher, while total and passive EFs decreased with age. Interracial differences were noted in LA volumes, without substantial differences in functional indices. Conclusion: Although similar normal values for LA volumes and strain can be applied to both sexes, meaningful differences in LA size occur with aging. Indices of function also shift with age, with a compensatory rise in booster function, which may serve to counteract observed lower total and passive EFs. Defining age associated normal values may help differentiate age-associated "healthy"LA aging from pathologic processes. (J Am Soc Echocardiogr 2022;35:154-64.