Figure 4

HL-1 cells were paced at 4Hz for 24 hours. Figure 4 shows that tachypacing induced intracellular oxidative stress from ROS in atrial myocytes and that metformin reversed this effect. Tachycardia induced myofibril degradation quantified by myosin heavy chain and troponin-I were also rescued by metformin of 1 mM.