FREEHAND 3-DIMENSIONAL ECHOCARDIOGRAPHY FOR MEASUREMENT OF LEFT-VENTRICULAR MASS - IN-VIVO ANATOMIC VALIDATION USING EXPLANTED HUMAN HEARTS

Objectives. We sought to validate freehand three-dimensional echocardi ography for measuring left ventricular mass and to compare its accurac y and variability with those of conventional echocardiographic methods . Background. Accurate measurement of left ventricular mass is clinica lly important as a predictor of morbidity and mortality, Freehand thre e-dimensional echocardiography eliminates geometric assumptions used b y conventional methods, minimizes image positioning errors using a lin e of intersection display and increases sampling of the ventricle. Pre liminary studies have shown it to have high accuracy and low variabili ty. Methods. Twenty-eight patients awaiting heart transplantation were examined by conventional and freehand three-dimensional echocardiogra phy. Left ventricular mass was determined by the M-mode (''Penn cube'' ) method, the two-dimensional truncated ellipsoid method and three-dim ensional surface reconstruction. The ventricles of 20 explanted hearts were obtained, trimmed and weighed, Echocardiographic mass by each me thod peas compared with true mass by linear regression, Accuracy, bias and interobserver variability were calculated. Results. For three-dim ensional echocardiography, the correlation coefficient, standard error of the estimate, root mean square percent error (accuracy), bias and interobserver variability were 0.992, 11.9 g, 4.8%, -4.9 g and 11.5%, respectively. For the two-dimensional truncated ellipsoid method they were 0.905, 38.5 g, 15.6%, 15.4 g and 23.3%. For the M-mode (''Penn-cu be'') method they were 0.721, 96.9 g, 53.0%, 109.2 g and 19.5%. Conclu sions. Freehand three-dimensional echocardiography for measurement of left ventricular mass has high accuracy and ion; variability and is su perior to conventional methods in hearts of abnormal size and geometry . (C) 1997 by the American College of Cardiology.