Anatomic validation of a novel method for left ventricular volume and mass measurements with use of real-time 3-dimensional echocardiography

Abstract

Assessment of left ventricular (LV) volumes and mass is a critical element in the evaluation of patients with cardiovascular disease. However, most non-invasive methods used for the quantitative measurements of LV volume and mass have important intrinsic limitations. Real-time 3-dimensional echocardiography (RT3D echo) is a new technique capable of acquiring volumetric images without cardiac or respiratory gating. The purpose of this study was to develop and validate a system for rapid LV volume and mass measurements with the use of RT3D echo images. To this end, in 11 explanted sheep hearts, the left ventricle was instrumented with a latex balloon and filled with known volumes of saline solution. Two independent observers made volume calculations from images acquired with RT3D echo. In addition, 21 open-chest sheep were imaged with RT3D echo for LV mass calculation. Anatomic LV mass was determined after removing the heart. A strong correlation was observed between the actual LV volumes and those calculated from the RT3D echo images (r = 0.99; y = 1.31 + 0.98x; standard error of the estimate = 2.2 mL). An analysis of intraobserver and interobserver variabilities revealed high indexes of agreement. A strong correlation was observed between actual LV mass and that calculated from RT3D echo images (r = 0.94; y = 14.4 + 0.89x; standard error of the estimate = 8.5 gm). Thus RT3D echo images allow rapid and accurate measurements of LV volume and mass. This technique may expand the use of cardiac ultrasonography for the quantitative assessment of heart disease.