Effect of echocardiographic imaging view and methods on left ventricular wall-thickness measurements in normal cats and cats with hypertrophic cardiomyopathy.
Echocardiographic measurements of left ventricular free wall (LVFW) and interventricular septum (IVS) thickness are essential for diagnosing hypertrophic cardiomyopathy (HCM).
To evaluate agreement between different imaging views and modes for assessing LV wall thickness in cats. We hypothesized that there is clinically relevant bias between methods, and that results cannot be used interchangeably.
Two-hundred eighty cats; 140 controls and 140 with subclinical HCM.
Retrospective, single-center, and cross-sectional study. End-diastolic IVS and LVFW thickness was evaluated by 2-dimensional (2D) and time-motion mode (M-mode) echocardiography, from right parasternal long-axis (RPLax) and right parasternal short-axis (RPSax) views: method-1 (M1), RPLax using 2D; M2, RPLax using M-mode; M3, RPSax using 2D; and M4, RPSax using M-mode. Using 2D images, the thickest portion of the LV wall was measured. Methods were compared using repeated measurement ANOVA on ranks and the Bland-Altman method with bias and 95% limits of agreement (95% LOA).
In controls, IVS thickness was not different among the 4 methods (P = .67; bias 0.04-0.10 mm, 95% LOA -1.09 to 1.28 mm); whereas LVFW thickness was (P < .001) using M-mode compared to 2D (bias 0.22-0.30 mm; 95% LOA -0.81 to 1.25 mm). In HCM cats, thickness of the IVS (bias -1.07 to -1.13 mm; 95% LOA -3.05 to 0.84 mm) and LVFW (bias 0.22 to -.27 mm; 95% LOA -2.09 to 2.03 mm) was different among methods (P < .001).
Two-dimensional and M-mode echocardiographic methods in the assessment of LV wall thickness cannot be used interchangeably, particularly in cats with HCM.
To evaluate agreement between different imaging views and modes for assessing LV wall thickness in cats. We hypothesized that there is clinically relevant bias between methods, and that results cannot be used interchangeably.
Two-hundred eighty cats; 140 controls and 140 with subclinical HCM.
Retrospective, single-center, and cross-sectional study. End-diastolic IVS and LVFW thickness was evaluated by 2-dimensional (2D) and time-motion mode (M-mode) echocardiography, from right parasternal long-axis (RPLax) and right parasternal short-axis (RPSax) views: method-1 (M1), RPLax using 2D; M2, RPLax using M-mode; M3, RPSax using 2D; and M4, RPSax using M-mode. Using 2D images, the thickest portion of the LV wall was measured. Methods were compared using repeated measurement ANOVA on ranks and the Bland-Altman method with bias and 95% limits of agreement (95% LOA).
In controls, IVS thickness was not different among the 4 methods (P = .67; bias 0.04-0.10 mm, 95% LOA -1.09 to 1.28 mm); whereas LVFW thickness was (P < .001) using M-mode compared to 2D (bias 0.22-0.30 mm; 95% LOA -0.81 to 1.25 mm). In HCM cats, thickness of the IVS (bias -1.07 to -1.13 mm; 95% LOA -3.05 to 0.84 mm) and LVFW (bias 0.22 to -.27 mm; 95% LOA -2.09 to 2.03 mm) was different among methods (P < .001).
Two-dimensional and M-mode echocardiographic methods in the assessment of LV wall thickness cannot be used interchangeably, particularly in cats with HCM.