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).
Real-time 3DE has become feasible as a standard clinical tool, but its accuracy for LV assessment has not been validated.
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.
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 inter- and intra-observer correlation between RT-3DE by two sonographers for volumes, ejection fraction, and mass.
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.