Assessment of left atrial size and geometry

By Elena Surkova, MD, PhD
Department of cardiac, thoracic and vascular sciences, University of Padua, School of Medicine, Padua, Italy

Clinical Case

  • 70-year-old woman
  • Clinical history of arterial hypertension and incomplete left bundle branch block
  • Cardiovascular risk factors include smoking and family history of coronary artery disease
  • Referred for echocardiographic assessment as a regular follow-up

Dilated aorta changed the LA geometry leading to irregular elongated shape of the chamber. Dilated aortic root also caused deformation of mitral annulus and mild mitral regurgitation. LA maximum volume was normal when measured by both biplane 2D echocardiographic methods (discs’ summation and area length).

LAV (MOD)      35 ml

LAVi (MOD)     23.1 ml/m2

LAV (AL)          37 ml

LAVi (AL)         24.4 ml/m2

3D echocardiographic data were acquired for better evaluation of morphology and size of the LA.
3D rendering (right bottom panel) demonstrates spatial relationships between cardiac structures and a very flat of the LA due the compression by the aortic root. The shape of the right atrium in transversal plane was relatively preserved.

Multi-beat 3D transthoracic LA dataset displayed in quad-view at the stage of alignment. To eliminate foreshortening, the vertical axis was set to get the longest diameter of the left atrium in all three planes. The entire 3D dataset then should be rotated clockwise (arrow) around its vertical axis, so that the four-chamber plane (dashed yellow line) crossed the middle part of both atriums and interatrial septum in a short-axis view.

Multi-beat 3D LA dataset displayed after obtaining optimal alignment. Note the difference in LA shape and size in comparison with corresponding standard 2D images (first panel) (no more foreshortening) and almost completely closed left ventricle (arrows) in four- and two-chamber planes.

LA Max Volume   53.2 ml

LA Max Volume index   35.1 ml/m2

LA Min Volume   30.2 ml

LA Min Volume index  19.9 ml/m2

LA Total EF   43.2%

Final result of the 3D echocardiographic volumetric analysis of the LA. 3D quantitation of the LA maximum volume allowed to reclassify the patient as having mildly enlarged LA and diagnose (together with E/E’=14,4) LV diastolic dysfunction.

Key messages

2D echocardiography:

  • Assessment of the LA volume is heavily dependent on the way 2D views are acquired;
  • 2D views, once acquired and recorded, cannot be modified anymore in their position and orientation;
  • Use of dedicated LA views are essential for accurate volumetric analysis of the LA;
  • In patients with unusual shape of LA, obtaining non-foreshortened LA views can be extremely complicated.

3D echocardiography:

  • Enables better understanding of spatial relationships between cardiac structures;
  • The orientation and the position of the cut-planes can be easily re-adjusted during post-processing without limitations, allowing to obtain anatomically sound, non-foreshortened LA views;
  • Provides accurate quantification of LA volumes and function.

References:

  1. Badano LP, Miglioranza MH, Mihaila S, Peluso D, Xhaxho J, Marra MP, Cucchini U, Soriani N, Iliceto S, Muraru D. Left atrial volumes and function by three-dimensional echocardiography: reference values, accuracy, reproducibility, and comparison with two-dimensional echocardiographic measurements. Circ Cardiovasc Imaging. 2016; 9. Epub ahead of print. doi: 10.1161/circimaging.115.004229.
  2. Lang RM, Badano LP, Tsang W, Adams DH, Agricola E, Buck T, et al., EAE/ASE recommendations for image acquisition and display using three-dimensional echocardiography. Eur Heart J Cardiovasc Imaging. 2016;13:1–46. doi:10.1093/ehjci/jer316.

Elena Surkova, MD, PhD

Dr. Elena Surkova is a clinical research fellow at the Department of Cardiac, Thoracic and Vascular Sciences, University of Padua School of Medicine in Padua, Italy.
She graduated from Samara State Medical University (Samara, Russia) and completed her training in Internal medicine, Cardiology, and PhD there. Then she developed interest in advanced cardiovascular imaging techniques, specifically in the deformation imaging and three-dimensional echocardiographic assessment of the right heart. She has been recently awarded long-term training and research fellowships from the ESC and EACVI.