Accurate quantification of left ventricular geometry and function

by Luigi P. Badano, MD, PhD, FESC, FACC
Department of cardiac, thoracic and vascular sciences, University of Padua, School of Medicine, Padua, Italy

Clinical Case

  • 51-year-old caucasian man
  • Hypertensive; NYHA class II
  • Old STEMI in the territory of left anterior descending coronary artery
  • Referred for echo assessment of left ventricular (LV)  size and function1

Two-dimensional 4-chamber view, showing a LV apical aneurysm, with normal wall motion in the mid and basal LV segments.

Two-dimensional 2-chamber view, showing a very limited dyskinesia of LV apex, and a good overall LV function.

Two-dimensional apical long-axis view demonstrates a large apical aneurysm, involving an important part of anterior septum.

Semi-automated analysis of LV volumes and ejection fraction by 3D echocardiography.

Volume-time curve and quantitative measurements of LV volumes and ejection fraction obtained by 3D echocardiography.

Using biplane disc-summation algorithm (modified Simpson’s method) on 4- and 2-chamber views, the following measurements were obtained:

  • LV end-diastolic volume = 112 ml;
  • LV end-systolic volume = 55 ml;
  • LV ejection fraction = 51 %

Using semi-automated border detection algorithm applied on 3D LV full-volume data set, the following measurements were obtained:

  • LV end-diastolic volume = 126 ml;
  • LV end-systolic volume = 70 ml;
  • LV ejection fraction = 44 %

When we use the 2D biplane (modified Simpson’s) algorithm to calculate the LV volumes and derive the ejection fraction by 2D echocardiography, we assume that the LV function displayed in 4-chamber and in 2-chamber apical views accurately reflects the actual global LV function.

However, the two tomographic planes used to assess LV function with 2D echocardiography (i.e. 4- and 2-chamber views) encompass only a very limited amount of the endocardial surface of the LV.

3D surface rendering of LV cavity, illustrating the added value of 3D echocardiography in LV volume quantification with respect to biplane calculation, which takes into account only a very limited part of LV endocardium confined in 4- and 2-chamber view

Key Messages

2D echocardiography:

  • The two tomographic planes used to assess LV ejection fraction with 2D echocardiography (i.e. 4- and 2-chamber views) encompass only a very limited part of LV endocardium.
  • Biplane Simpson’s method neglects the contribution of wall motion abnormalities localized in the infero-lateral or antero-septal walls to LV ejection fraction impairment
  • In addition, the geometric assumptions of biplane Simpson’s method do not verify in presence of wall motion abnormalities.
  • Therefore, in patients with extensive wall motion abnormalities, LV ejection fraction by 2D echocardiography may be misleading

3D echocardiography:

  • Takes into account the entire LV endocardial surface
  • Is independent from any geometric assumption about the shape of the LV cavity.
  • As a consequence, it provided LV volumes and ejection fraction that were closer to the values obtained from cardiac magnetic resonance.

References

  • Lang RM, Badano LP, Tsang W, et al. EAE/ASE recommendations for image acquisition and display using three-dimensionalechocardiography. Eur Heart J Cardiovasc Imaging. 2012;13(1):1-46.
  • Lang RM, Badano LP, MOr-Avi V et al. Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr 2015; 28:1-39