Background: Deriving mitral regurgitant fraction relies on accurate determination of left ventricular (LV) volumes. Many linear and planar echocardiographic methods, in different orientations and number of planes, are clinically practical, but have not been comprehensively evaluated against real-time three-dimensional echocardiographic volume (3DV).Hypothesis/
Objectives: Identify the LV volumetric approaches that generate the best agreement and interoperative reproducibility compared to 3DV across varying disease severities.Animals: Sixty client-owned dogs with myxomatous mitral valve disease (38 Stage B1, 13 Stage B2, 9 Stages C/D) received echocardiograms, with a subset of 29 dogs imaged by two operators.
Methods: Prospective method comparison study. End-diastolic and end-systolic LV volumes calculated via linear methods in long- and short-axis (Teichholz, cubed, modified cubed), monoplane methods in right parasternal and left apical views (area-length and Simpson’s method of disc), biplane Simpson’s method of disc, and real-time triplane were compared against 3DV using Bland-Altman analysis and concordance correlation coefficients. Interoperator reproducibility was assessed via intraclass correlation coefficients and reproducibility coefficients.
Results: The linear methods overall had substantial bias and poor agreement compared to 3DV (Table 1). Amongst the monoplane methods, the right parasternal view provided better agreement and interoperator reproducibility, particularly in systole (Table 2), than the left apical view. Amongst the multiplane methods, only triplane offered improved agreement above the monoplane methods, although its interoperator reproducibility in systole was worse. Interoperator reproducibility was poor with 3DV.Conclusions and clinical importance: No single method appeared consistently superior. The results of this study help delineate the limitations of each method.
