Repeatability and reproducibility of feline echocardiographic left ventricular myocardial area and left ventricular...

This study aimed to evaluate the repeatability and reproducibility (R&R) of left ventricular myocardial area (LVMA) measurements and linear left ventricular wall thickness measurements.

A retrospective study was conducted; apparently normal echocardiograms from 50 cats were included. Using right parasternal two-dimensional short-axis echocardiographic images at the level of the papillary muscles, LVMA, left ventricular myocardial area including papillary muscles (LVMAP), interventricular septum thickness at end-diastole (IVSd), and left ventricular posterior wall thickness at end-diastole (LVPWd) were recorded. Ten echocardiograms were randomly selected for R&R assessment by three observers on three separate occasions each. Concordance between observers was assessed using Kendall's W, and measurement system variance was analyzed via Gage R&R, using a random-effects model.

Median (minimum-maximum) of measurements from the 50 echocardiograms were as follows: LVMA: 2.46 cm² (1.44-3.20 cm²), LVMAP: 2.92 cm² (1.79-3.88 cm²), IVSd: 3.94 mm (3.11-5.21 mm), and LVPWd: 4.37 mm (2.74-5.18 mm). The LVMAP showed the highest interobserver concordance (Kendall's W, 0.85) and lowest measurement-system variability (Gage R&R, 6.57%), whereas IVSd and LVPWd had lower concordance (0.67 and 0.60, respectively) and higher Gage R&R values (17.88% and 13.22%, respectively).

Measurements were based on preselected high-quality cine loops and may not reflect variability encountered in real-world practice. All echocardiograms were acquired from a single machine and included only apparently normal echocardiograms, limiting generalizability to diseased populations or diverse imaging systems.

The LVMAP has good R&R. Further studies are warranted to validate LVMAP's diagnostic utility.