eproducibility and Accuracy of Echocardiographic easurements of Left Ventricular Parameters sing Real-Time Three-Dimensional Echocardiography
OBJECTIVES We sought to determine whether assessment of left ventricular (LV) function with real-time (RT) three-dimensional echocardiography (3DE) could reduce the variation of sequential LV measurements and provide greater accuracy than two-dimensional echocardiography (2DE). BACKGROUND Real-time 3DE has become feasible as a standard clinical tool, but its accuracy for LV assessment has not been validated. METHODS Unselected patients (n 50; 41 men; age, 64 8 years) presenting for evaluation of LV function were studied with 2DE and RT-3DE. Test-retest variation was performed by a complete restudy by a separate sonographer within 1 h without alteration of hemodynamics or therapy. Magnetic resonance imaging (MRI) images were obtained during a breath-hold, and measurements were made off-line. RESULTS The test-retest variation showed similar measurements for volumes but wider scatter of LV mass measurements with M-mode and 2DE than 3DE. The average MRI end-diastolic volume was 172 53 ml; LV volumes were underestimated by 2DE (mean difference, 54 33; p 0.01) but only slightly by RT-3DE ( 4 29; p 0.31). Similarly, end-systolic volume by MRI (91 53 ml) was underestimated by 2DE (mean difference, 28 28; p 0.01) and by RT-3DE (mean difference, 3 18; p 0.23). Ejection fraction by MRI was similar by 2DE (p 0.76) and RT-3DE (p 0.74). Left ventricular mass (183 50 g) was overestimated by M-mode (mean difference, 68 86 g; p 0.01) and 2DE (16 57; p 0.04) but not RT-3DE (0 38 g; p 0.94). There was good interand intra-observer correlation between RT-3DE by two sonographers for volumes, ejection fraction, and mass. CONCLUSIONS Real-time 3DE is a feasible approach to reduce test-retest variation of LV volume, ejection fraction, and mass measurements in follow-up LV assessment in daily practice. (J Am Coll Cardiol 2004;44:878–86) © 2004 by the American College of Cardiology Foundation