Quantification of regional volume and systolic function of the left ventricle by real-time three-dimensional echocardiography.

Real-time three-dimensional (3D) echocardiography (RT-3DE) provides a unique technique to evaluate left ventricular regional function in a 3D format. We aimed to explore whether the left ventricular segmental volume and systolic function is uniform and to establish normal values of volume and systolic function parameters of 16 regions in healthy subjects. RT-3DE was performed in 41 normal subjects and four-dimensional (4D)-left ventricle (LV) analysis software and a TomTec workstation were used to analyze data for regional end-diastolic volume (EDV(R)), regional end-systolic volume (ESV(R)), regional stroke volume (SV(R)), regional ejection fraction (EF(R)), ratio of SV(R) to global SV (SV(R/G)) and ratio of SV(R) to global EDV (EF(R/G)). All regional volume and systolic function parameters were not uniform among the left ventricular walls. They all increased in the order of inferior, posterior, lateral, septal, anterior and antero-septal walls with an increasing trend from the apical, middle to basal segments. The systolic function (EF(R), SV(R/G) and EF(R/G)) of the anterior and antero-septal walls was significantly higher than that of the lateral, inferior and posterior walls. And the intra- and interobserver variability for EDV(R), ESV(R), SV(R/G) and EF(R/G) ranged from 2.9% to 5.8%. In conclusion, the regional volume and systolic function of the left ventricle is not uniform and, therefore, a normal left ventricle cannot be regarded as a symmetric model for assessing the regional systolic function. This information may improve the accuracy of RT-3DE techniques in the assessment of the left ventricular regional function. (E-mail: zhangyun@sdu.edu.cn and yaogh@yahoo.com).