Transducer Position & LV Geometry

Transducer Position & Left Ventricular Geometry

Learn to position the transducer correctly to avoid long axis foreshortening

April 14th, 2022
Pages 1-8


  • Ultrasound transducer
  • Left ventricular long axis
  • Foreshortening
  • Left ventricular geometry
  • Left ventricular volumes and ejection fraction
  • Apical views

Qualitative evaluation of EF.
The qualitative “eyeball” method” of quantifying LV ejection fraction (EF) is widely used, especially in the USA, supported by the Literature. A 1997 English study found that the “eyeball” estimate of LV function was of prognostic significance (relative risk of poor vs. good, 2.248, p<.001). No other quantitative echo index was of independent prognostic significance when all variables were tested in a regression model.
Reference: Prognostic implications of qualitative assessment of LV function compared to simple routine quantitative echocardiography (Silcocks et al. Heart 1997;78:237, Sheffield, UK)

The qualitative “eyeball” method relies more heavily than the quantitative Simpson method to calculated EF on the quality of the acquired imaging, and I am referring here to the achievement of a correct LV geometry. This is because when using the Simpson method we have immediate evidence of the LV long axis and volume in each view (4-chamber and 2-chamber).

Figure 1. tt2043.
Let’s now consider this 4-chamber view obtained in a patient during a postoperative outpatient follow-up for an aortic valve mechanical prosthesis. This is a real case scenario.
The calculated (Simpson method) end-diastolic volume was 234 ml and the EF= 66.2 %, with normal function of the valve prosthesis.

What do you think of the quality of the imaging and of the LV geometry: is it correct ? Would you rely on these numbers ?

Well: no. The geometry is clearly not correct, and consequently the numbers are unreliable. Let’s see how we can simply and quickly reach this conclusion.

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