There are areas in the heart called pacemakers that send electrical signals to the rest of the heart, setting the speed or pace of the heartbeat. These pacemakers speed the heart up during exercise or hard work and slow it down again during rest. If natural pacemakers are injured or fail to do their job, a miniature medical device called a cardiac pacemaker can be implanted in the chest wall.
What is the Body’s Natural Pacemaker?
The heart’s natural pacemaker is called the sinoatrial node, or sinus node. It’s a small mass of specialized cells in the top of the heart’s right atrium (upper chamber). It makes the electrical impulses that cause the heart to beat. A chamber of the heart contracts when an electrical impulse moves across it. For the heart to beat properly, the signal must travel down a specific path to reach the ventricles, the heart’s lower (pumping) chambers.
When the heart’s natural pacemaker is defective, a person’s heartbeat can be too fast, too slow or irregular – or the heart’s electrical pathways may also be blocked.
What is an Artificial Pacemaker?
An artificial pacemaker is a small, battery-operated device that primarily keeps the heart from beating too slowly. Some pacemakers are permanent (internal) and some are temporary (external). Artificial pacemakers range from simple to sophisticated.
- A pacemaker sends electrical impulses to the heart to help it pump properly. An electrode is placed next to the heart wall and small electrical charges travel through the wire to the heart.
- Most pacemakers are demand pacemakers, meaning they have a sensing device that turns the signal off when the heartbeat is above a certain level, and back on when the heartbeat is too slow.
Placement of a Pacemaker
Pacemaker implantation usually takes place in a Cardiac Catheterization Lab while the patient is sedated, but awake. The patient is given local anesthesia so there is no pain. The pacemaker usually is implanted in the upper chest and the wire leads are threaded through a vein into the heart. The battery is attached to the leads and placed under the patient’s skin. The leads must touch the inside of the heart so the electrical signals can be carried back and forth between the heart and the battery. In some cases, the patient may need a temporary pacemaker, which is placed outside the body and removed once the permanent pacemaker is implanted.
Side Effects of Artificial Pacemakers
There are few side effects or surgical complications associated with artificial pacemakers. To varying degrees, all pacemakers are sensitive to electrical interference from strong magnetic fields, electrical generators and similar equipment, depending upon how well shielded they are. Patients are encouraged to carry a letter or identification card stating that they have an artificial pacemaker. They should also inform their dentists and other healthcare providers of their conditions. Like any man-made device, pacemakers are subject to failure and do need to be checked regularly. FBN
By Lynn Otto, M.D.
Lynn Otto, M.D., is a board-certified cardiologist and electrophysiologist at the Heart & Vascular Center of Northern Arizona. She specializes in the electrical activities of the heart including diagnosing and treating irregular heart rhythms and implanting and managing heart devices such as pacemakers and defibrillators.
The Heart & Vascular Center of Northern Arizona is a physician practice offering services ranging from general cardiology and the treatment of chronic heart and vascular conditions to advanced surgical techniques, including traditional and minimally invasive open heart surgery. Cardiovascular specialists include cardiologists, interventional cardiologists, an electrophysiologist, cardiothoracic and vascular surgeons, and specialty trained physician assistants, nurse practitioners and registered nurses. The center is a partnership between Flagstaff Medical Center and Verde Valley Medical Center, with offices located in Camp Verde, Cottonwood, Flagstaff, Sedona, Village of Oak Creek, Williams and Winslow.
To schedule an appointment with Dr. Otto or any of the cardiovascular physicians at the Heart & Vascular Center of Northern Arizona, call 928-773-2150. For more information, visit NAHeartCare.com.