What Is a Pacemaker?

A cardiovascular and thoracic surgeon with more than two decades of experience, Dr. Marvin Derrick presently sees patients at DMH Heart & Lung Institute and serves as director of Decatur Memorial Hospital Cardiothoracic Surgical Services. In addition to major surgical procedures on the blood vessels, heart, and lungs, Dr. Marvin Derrick performs minor surgeries such as pacemaker placement.

The heart has an electrical system that controls the speed and rhythm of the heartbeat to keep blood flowing properly throughout the body. A disruption in this electrical system, which is called heart arrhythmia, can cause a fluttering sensation in the heart, a heartbeat that is faster or slower than normal, shortness of breath, chest pain, and fainting. Heart arrhythmias stem from a variety of conditions and lifestyle factors, including heart disease, congenital heart problems, smoking, and the use of certain medications.

A pacemaker is a small electronic device that replaces the body’s own natural electrical system when the heartbeat is too slow. Implanted in the chest, the pacemaker is comprised of two parts. The pulse generator contains a small computer and a battery and is placed just under the skin near the heart. The leads are insulated wires that connect the pulse generator to the heart muscle. The pacemaker is programmed by the surgeon to send an electrical impulse to the heart when the heart rate drops to a certain level, or when the heart stops beating altogether. This stimulation causes the heart muscle to contract and beat so that it maintains a steady rate and rhythm.