Abstract 18100: Intertechnique Differences for Measurements of Left Volume and Ejection Fraction Between Two-dimensional Echocardiography and Real Time Three-dimensional Echocardiography Using Single Beat Full-volume Acquisition in Patients with Regional Wall Motion Abnormality

Abstract

Introduction: Conventional two-dimensional echocardiography (2DE) for assessment of left ventricular (LV) volume and systolic function are dependent on geometric assumptions of LV shape and at risk of underestimating volume in foreshortened view. Especially, in patients with regional wall motion abnormality (RWMA), the measurements of LV volume and ejection fraction (EF) by 2DE could be affected by altered LV geometry and location of RWMA.

Objectives: The aim of this study was to compare volumetric assessment by 2DE with those of real time three-dimensional echocardiography (RT3DE) in patients with or without RWMA.

Methods: Three-hundred eighty seven consecutive patients who underwent 2DE and RT3DE were classified as normal EF (n=193), global hypokinesia (n=40), and RWMA at either anterior (n=49), lateral (n=47), and inferior wall (n=58). LV volumes and EF were measured by 2DE (Simpson’s biplane method) and RT3DE using the single beat full-volume acquisition technique.

Results: The mean LVEF by RT3DE was 63% ± 5% in patients with normal EF, 30% ± 11% in global hypokinesia, 44% ± 4% in anterior RWMA, 49% ± 5% in lateral RWMA and 51% ± 5% in inferior RWMA. Significant correlations between 2DE and RT3DE were observed for LV volumes and EF in patients with normal EF, global hypokinesia, anterior and inferior RWMA (p<0.01 for all). However, in patients with lateral RWMA, EF by 2DE was larger than that by RT3DE (52ml ± 5ml vs 49ml ± 5ml, respectively, p=0.007) and showed no correlation with EF by RT3DE (r=0.18, p=0.26). Bland-Altman plots revealed poor agreement for EF between the two techniques in patients with lateral RWMA (bias 3.4%, 95% limit of agreement 17.5% to -10.6%). Both inter- and intraobserver reliability of 2DE and RT3DE were excellent for LV volumes and EF, respectively.In conclusion, EF by 2DE in patients with lateral RWMA was larger and showed poor agreement with EF by RT3DE, which reveals the limitation of two-dimensional biplane measurement excluding the lateral wall.