Metformin improved left ventricular structure and function, as well as, cardiac hypertrophy in mice following myocardial ischemia and reperfusion. (A) Murine in vivo heart failure protocol. (B) Left ventricular end diastolic diameter (LVEDD) (C) left ventricular end systolic diameter (LVESD) and (D) Ejection fraction were calculated using two-dimensional B-mode echocardiography images at baseline and following myocardial ischemia in all groups (E) Heart to body weight (H/BW) ratio used as a measure of cardiac hypertrophy. Values are means ± S.E.M. Numbers inside bars indicate the number of animals that were investigated in each group. *** p < 0.001 vs. Baseline, ** p < 0.01 vs. Sham, * p < 0.05 vs. Sham. Veh = vehicle, Met = Metformin, Met QD = Metformin QD.