SOD1 and myocardial infarction: We then tested myocardial oxidative stress injury and cardiac function and observed that MI mice had raised malondialdehyde and ROS contents and impaired SOD activity (Figure 3C through 3E), as well as increased LVEDD, LVESD, and heart rate, and decreased LVEF and LVFS (Figure 3F through 3H), indicating that oxidative stress was enhanced and cardiac function was destroyed after MI.