What Is It?
A pacemaker is an implanted device that regulates your heartbeat electronically. It monitors your heart's rhythm and, when necessary, it generates a painless electric impulse that triggers a heartbeat.
Your pacemaker is programmed to meet the needs of your heart. Early pacemakers were implanted to treat bradycardia, an abnormally slow heartbeat. Now pacemakers can be programmed to treat a variety of heart problems, including heart failure.
The electronic control center of your pacemaker — the part that is programmed by your doctor — is called the pulse generator. The pulse generator is a unit encased in titanium that usually is placed under the skin below your collarbone. In most cases, the unit is small, often weighing less than 30 grams (about 1 ounce). A lithium iodide battery inside the generator lasts 5 to 12 years, with an average of 7 to 8 years. Other sophisticated electronic components are responsible for: