In Vivo Assessment of Cardiac Function

Cardiac function was evaluated by carrying out transthoracic echocardiography at day 3, and day 21 post surgery using the Vevo^®2100 Imaging System Visualsonics following a previously established procedure.51 After the mice were anesthetized using isoflurane gas, 2D images of hearts were obtained for M-modes through the anterior and posterior left ventricle (LV) walls. Indices of left ventricle (LV) systolic function including LV ejection fraction (EF), LV fractional shortening (FS), cardiac output (CO), and stroke volume (SV) were calculated using the following formulae2,47,51:

where, LVEDd corresponds to the end-diastolic diameter of the left ventricle and LVESd is the end-systolic diameter of the left ventricle measured from three consecutive cardiac cycles. EDV is the end-diastolic volume and ESV corresponds to the end-systolic volume.