Age- and Gender-Dependency of Left Ventricular Geometry Assessed with Real-Time Three-Dimensional Transthoracic Echocardiography

Background: Aging and gender may affect left ventricular (LV) mechanics. The aim of this study was to determine the age and gender dependency of LV mechanical indices obtained from real-time three-dimensional echocardiography (RT3DE). Methods: RT3DE was performed in 280 healthy subjects (age range, 1-88 years; 137 men). From full-volume data sets, LV endocardial and epicardial borders were semiautomatically traced using quantitative software. LV volumes and corresponding long-axis diameter were measured throughout the cardiac cycle. Sphericity index was defined as the ratio of LV volume and spherical volume, calculated as 4/3 x pi x (long-axis diameter/2)(3). LV mass was calculated as (LV epicardial volume - LV endocardial volume) x 1.05. The ratio of LV mass to LV volume was also calculated. Results: The mean value of LV ejection fraction did not change with age. However, LV volumes, mass, sphericity index, and LV mass/volume ratio were altered by age: (1) sphericity index was highest in the first decade of age and then declined until the fifth decade, (2) LV mass/volume ratio significantly increased in older age, and (3) LV mass/volume ratio was significantly higher in aged women compared with age-matched men. Conclusions: Age has heterogeneous effects on LV shape and LV mass/volume ratio, potentially due to the growing process of myocardial fibers and the surrounding architecture in the younger population, as well as the aging process, with an increase in vascular stiffness and a loss of myocytes in older populations. Higher LV mass/volume ratios in older women might be a contributor to the preferential development of diastolic heart failure in this population. (J Am Soc Echocardiogr 2011;24:541-7.)