Effect of ALDH2 overexpression and knockout (KO) on ischaemia/reperfusion (I/R)-induced myocardial injury. Effect of ALDH2 overexpression and KO on myocardial infarct size, fraction shortening, and post-ischaemic left ventricular function was evaluated following ischaemia (20 min)/reperfusion (4 h for panels A and B and 30 min for C and D). (A) Myocardial infarct size with representative tissue sectioning; (B) echocardiographic fraction shortening; (C) left ventricular developed pressure (LVDP)-heart rate (HR) product; and (D) maximal velocity of pressure development (+dP/dt). Mean ± SEM, n = 5–6 hearts per group, *P < 0.05 vs. wild-type (WT) group, #P < 0.05 vs. WT + I/R group.