Comparison of M-mode and two-dimensional echocardiographic algorithms used to estimate left ventricular mass: the...

Left ventricular (LV) mass as measured from M-mode echocardiography has been shown to be an important predictor of subsequent cardiovascular morbidity and death. Investigators have debated the advantages of LV mass calculations derived from M-mode versus various two-dimensional (2D) echocardiographic algorithms. The purpose of this study was to compare measurements of LV mass made from M-mode and 2D echocardiographic formulas in 325 healthy young adults of the Coronary Artery Risk Development in Young Adults cohort. M-mode LV mass was calculated according to a necropsy-validated formula, whereas 2D LV mass was calculated according to two established algorithms (i.e., the biplane Simpson and truncated ellipsoid methods). LV mass derived from M-mode echocardiography was 162.7 +/- 52 gm (mean +/- SD). Mean (+/- SD) LV mass derived from 2D echocardiographic measurements were as follows: with the biplane Simpson method (four-chamber view), 164.2 +/- 42 gm; with the biplane Simpson method (two-chamber view), 159.8 +/- 44 gm; with the truncated ellipsoid method (four-chamber view), 139.8 +/- 37 gm; and with the truncated ellipsoid method (two-chamber view), 143.1 +/- 38 gm. Correlations between M-mode and 2D methods ranged from 0.75 to 0.81 (p < 0.0001 for each comparison), and correlations between 2D methods were all greater than 0.90. This study has demonstrated that measurements of LV mass calculated from M-mode and 2D formulas correlate well with each other. Nonetheless, LV mass calculated from the truncated ellipsoid formula averages approximately 20 gm less than that calculated from the 2D biplane Simpson or M-mode echocardiographic formulas. These systematic differences in calculated values for LV mass must be taken into account when choosing an LV mass algorithm for use in cross-sectional and serial studies.