2.5 Echocardiography
Echocardiography was performed using a Doppler echocardiography system (Vevo 2100; Visual Sonics, Toronto, Canada), and mice were anesthetized with 1% isoflurane inhalation during the examination. The left atrial diameter (LAD) was then calculated using B-mode images, and the other parameters were calculated at the end of systole and diastole using M-mode images.