Keeping the Beat: Artificial Pacemakers

Artificial pacemakers are electronic devices that act in place of the heart’s natural pacemaker (the sinus or sinoatrial node). They generate electrical impulses that initiate each heartbeat. Pacemakers consist of a battery, an impulse generator, and wires that connect the pacemaker to the heart.

An artificial pacemaker is implanted surgically. After a local anesthetic is used to numb the insertion site, the wires that connect the pacemaker are usually inserted into a vein near the collarbone and threaded toward the heart. Through a small incision, the impulse generator, which is about the size of a silver dollar, is inserted just under the skin near the collarbone and connected to the wires. The incision is stitched closed. Usually, the procedure takes about 30 to 60 minutes. The person may be able to go home shortly afterward or may briefly stay in the hospital. The battery for a pacemaker usually lasts 10 to 15 years. Nevertheless, the battery should be checked regularly. Battery replacement is a quick procedure.

There are different types of pacemakers. Some take over the control of the heart rate, overriding the electrical impulses generated by the heart. Others, called demand pacemakers, allow the heart to beat naturally unless it skips a beat or begins to beat at an abnormal rate. Still others, called programmable pacemakers, can do either. Some pacemakers can adjust their rate depending on the wearer’s activity, increasing the heart rate during exercise and decreasing it during rest.