Sex differences in the evolution of left ventricle remodeling in rats with severe volume overload

Figures

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  Fig. 1. Left ventricular dimensions increases more strongly in female AR rats than in males compared to sham-operated animals. End-diastolic (EDD; a and b), end-systolic (ESD; d and e) LV diameters and septum thickness (IVSW; g and h) were measured in M-mode LV short axis (SAX) and parasternal long axis (PSLAX) views in sham (blue) and AR (red) male and female rats at four different time points over a 6 months after surgery. Relative wall thickness (RWT; j and k) was then calculated using the equation described in the Methods section. Ratios of the mean values for each parameter in AR rats over sham ones was calculated for each time point and are illustrated in Panels c, f, i and l. Results are expressed as mean ± standard error of the mean (SEM; N = 8–10 animals/group). *: p < 0.05 and **: p < 0.01 between corresponding sham and AR groups at a given time point

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  Fig. 2. Left ventricular volumes increase more strongly in female AR rats than in males compared to sham-operated animals. End-diastolic (EDV; a and b) and end-systolic (ESV; d and e) LV volumes were estimated using three-dimensional reconstruction of stacked LV short axis (SAX) views in sham (blue) and AR (red) male and female rats at four different time points over a 6 months after surgery. LV ejection fraction (EF; g and h) stroke volume (SV; j and k) were then calculated using the equation described in the Methods section. Ratios of the mean values for each parameter in AR rats over sham ones was calculated for each time point and are illustrated in Panels c, f, i and l. Results are expressed as mean ± standard error of the mean (SEM; N = 8–10 animals/group). *: p < 0.05 and **: p < 0.01 between corresponding sham and AR groups at a given time point

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  Fig. 3. Comparison of various echo methods to estimate ejection fraction and LV mass. Means ±SEM of calculated ejection fractions either using M-mode SAX view (X-axis) or three-dimensional reconstruction of stacked LV short axis (3DSAX) views (Y-axis) were plotted for each time point (red; months) for sham (a and c) and AR (b and d) groups. The oblique solid line represents the expected results if both methods were equivalent. In panels e and f are shown the correlation of estimated LV mass by echo (Y-axis) compared to wet LV weights obtained at the end of the protocol at 6 months. Two equations described in the Methods section were used to estimate LV mass in blue and red, respectively. Slope ± SEM for each regression line is indicated. The oblique solid line represents the expected results if methods were equivalent

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  Fig. 4. Evidence of a sex dimorphism in the LV geometry of the dilated AR left ventricle. a. Representative end-diastolic parasternal long axis (PSLAX) LV views from 6-month sham (up) and AR (bottom) rats of both sexes (left: females and right: males). Images were calibrated in order to be at the exact same scale. Vertical and horizontal bars correspond to 3 mm. b. From the PSLAX LV end-diastolic views at 6 months of sham and AR rats, three diameters were determined (EDD1 to 3). EDD1 represents the normal EDD from data or Table 2. The bottom part of the LV was then divided into thirds along the longitudinal axis (orange line) and EDD2 and EDD3 were determined. c. Ratio of EDD2/EDD1 (top) and EDD3/EDD1 (bottom) were plotted for male and female sham and AR animals at 6 months. Results are expressed as mean ± standard error of the mean (SEM; N = 8–11 animals/group). *: p < 0.05 between indicated groups

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  Fig. 5. Evolution of global LV strain rates in male and female sham and AR rats. Global longitudinal (a and b) and circumferential (c and d) strain rates were calculated from parasternal long axis LV views in sham (blue) and AR (red) male and female rats at four different time points over a 6 months after surgery. Results are expressed as mean ± standard error of the mean (SEM; N = 8–10 animals/group). **: p < 0.01 between corresponding sham and AR groups at a given time point