Repeatability and agreement of real time three-dimensional echocardiography measurements of left ventricular mass and synchrony in young patients.

BACKGROUND: Left ventricular mass (LVM) and synchrony have prognostic value for many cardiovascular disease states. We report the agreement and repeatability of LVM estimation by three-dimensional (3D) versus M-mode and repeatability of 3D estimation of systolic dyssynchrony.

METHODS: 3DLVM was computed by subtraction of endocardial from epicardial volume X1.05 both at end-diastole and end-systole. M-mode measurements were made at end-diastole. This prospective study comprised 40 subjects, 20 patients with chronic kidney disease or treated neuroblastoma and 20 healthy individuals. The median age was 17 (range 6-29 years).

RESULTS: Intra- and inter-observer intraclass correlation was excellent for 3D systolic LVM (0.99, 0.87), 3D diastolic LVM (0.99, 0.93), M-mode LVM (0.88, 0.93), moderate for 16-segment SDI (0.77, 062), moderate to low for 12-segment SDI (0.48, 0.73), and 6-segment SDI (0.37, 0.69). The median (range) LVM measurement for 3D diastolic LVM was 125 g (50-253), 3D systolic LVM 109 g (40-195), and M-mode LVM 115 g (range 40-207). There was a significant bias for diastolic 3DLVM to be higher than systolic 3D or M-mode. Limits of agreement between methods were wide. The median (range) systolic dyssynchrony measurements were 2.0 (0.4-7.0), 1.5 (0.3-4.3), and 1.4 (0.3-4.5) for 16-segment, 12-segment, and 6-segment models, respectively.

CONCLUSION: 3D and M-mode measurement of LVM are highly repeatable. Measurement bias and wide limits of agreement mean that the same echocardiographic technique should be used during follow-up. Measurement of 3D systolic dyssynchrony is most repeatable using a 16-segment model.