Echocardiography and Hemodynamic Monitoring in Mice

Transthoracic echocardiography was performed by a MyLab 30CV ultrasound (Esaote SpA, Genoa, Italy) with a 10 MHz phased array transducer as previously described^{56 (link),57 (link)}. Light anesthetized by 1.5% isoflurane, mice were lightly secured in a warming pad with a shallow left lateral position after the precordium shaved. After imaged with two-dimensional (2D) mode in the parasternal long-axis and/or parasternal short-axis at the level close to papillary muscles, a 2D guided M-mode trace crossing the anterior and posterior wall of the left ventricle was recorded and the morphological parameters of the heart were collected and calculated. Attention was given not to bring excessive pressure to the chest, which could cause bradycardia and deformation of the heart.
Invasive hemodynamic monitoring was performed by cardiac catheterization according to our previous articles^{56 (link),57 (link)}. In brief, mice was placed on a warmed surgical platform with supine position and the right carotid artery was isolated, exposed. Then a 1.4-French Millar catheter transducer (SPR-839; Millar Instruments, Houston, TX) was inserted into the left ventricle through the isolated carotid artery. And data were analyzed using the PVAN data analysis software.