These are devices that are placed in your body, usually by surgery, to support the electrical system in your heart. They can stabilize abnormal heart rhythms and prevent problems that can disrupt or endanger your life. How do pacemakers work? Your heart has its own electrical system, which tells your heart’s chambers when it’s their turn to squeeze. When your heart’s electrical system malfunctions, your heart’s chambers may squeeze in the wrong order or squeeze too weakly to provide enough blood to your body. Pacemakers use electrical impulses to correct these kinds of malfunctions.