Abstract 1576: Left Atrial Volume by Real-time Three-Dimensional Echocardiography: Validation by Multidetector Computed Tomography
Background: Left atrial (LA) enlargement has been suggested as a barometer of diastolic dysfunction. Two-dimensional (2D) echocardiography systematically underestimate LA volume when compared with CT, but the accuracy of three-dimensional (3D) echocardiography is not well known.
Methods: To evaluate the accuracy of 3D echocardiography for determining LA volume, we compared LA volume measurements by echocardiography to that measured by 64-slice multidetector CT (MDCT) as a gold standard. LA volume by 3D echocardiography was measured on end-systolic frames with manual tracing using software (Philips, QLab). LA volume by MDCT was measured using workstation (AZE Ltd). The correlation coefficient comparing echocardiographic results versus the MDCT volumes was computed using linear regression.
Results: We prospectively evaluated 57 consecutive patients (mean age 66 ± 11 years, 59% men) who were referred to echocardiography and MDCT on the same day. The average LA volume was 52 ± 12 (range 32–90) mL by MDCT, and 48 ± 12 (range 29 – 85) mL by 3D echocardiography. LA volume by 3D echocardiography correlated closely with that by MDCT (r=0.94, P<0.0001)(Fig⇓.). 3D echocardiography underestimated MDCT measurements by 8% (4.1 ± 2.8 ml, P<0.0001). LA volume by 2D echocardiography (biplane area-length; mean 43 ± 10; range 26 – 65 mL) collated less well with that measured by MDCT (r=0.86, P<0.0001), and consistently underestimated LA volume by 19% (9.8 ± 5.1 mL, P<0.0001).
Conclusion: LA volume assessment by 3D echocardiography correlated closely with that measured by MDCT, albeit an 8% underestimation. 3D echocardiography may be a feasible noninvasive method to evaluate LA volume.