Echocardiographic measurements of left ventricular mass by a non-geometric method

The accuracy of a new non-geometric method for calculating left ventricular myocardial volumes from 2-D echocardiographic images was assessed in vitro using 20 formalin-fixed normal human hearts. Serial oblique short axis images were acquired from one point at 5 degree intervals, for a total of 10 to 12 cross sections. Echocardiographic myocardial volumes were calculated as the difference between the volumes defined by the epi- and endocardial surfaces. Actual myocardial volumes were determined by water displacement. Volumes ranged from 80 to 174 ml (mean 130.8 ml). Linear regression analysis demonstrated excellent agreement between echocardiographic (X) and direct measurements (Y) i.e., y = 0.98 X + 4.3 ml; r = 0.94; SEE = 8.4; p = 0.001. Comparison of 10 duplicate measurements by two independent observers yielded an r of 0.96. These in vitro results suggest that with this technique, quantitative analysis of a limited number of cross sectional echocardiographic views will provide accurate left ventricular mass estimates.