Mouse echocardiography

Mouse transthoracic echocardiography was performed using a Vevo 2100 High-Resolution Imaging System (FUJIFILM VisualSonics, Toronto, ON, Canada) on mice anesthetized initially by 4% isoflurane in 1 L/min of O₂ and then by 0.5–3.0% isoflurane and placed on a heated platform, as described previously [36]. We imaged the heart in the parasternal long-axis view in both 2D and M-modes. We obtained the following parameters using the software on the system: left ventricular ejection fraction (LVEF, %), fractional shortening (FS, %), left ventricular internal diameter in systole (LVIDs, mm), left ventricular internal diameter in end-diastole (LVIDd, mm), interventricular septum thickness in end diastole (IVSd, mm), left ventricular posterior wall thickness in end diastole (LVPWd, mm), and LV mass (mg). For the initial characterization of fortilin^KO-heart mice, the baseline echo was obtained when they were 7 weeks of age.