WHAT IS A PACEMAKER?: Although the heart has its own natural pacemaker that sets its rhythm, the "pacemaker" most commonly refers to an artificial electronic device that is implanted into the chest to regulate the heart's rhythm. Generally, pacemakers correct an abnormally slow heartbeat by sending electrical impulses to one or more chambers of the heart. These signals make the heart contract in a more regular rhythm than the chamber would otherwise.
WHAT ARE THE PARTS OF A PACEMAKER?:
- The Pulse Generator: The pulse generator contains a battery that supplies the electrical energy, and circuitry that transforms the energy into small electrical impulses. The circuitry controls the timing of the electrical impulses delivered to the heart. In addition, the pacemaker has a connector block to attach the pacing lead(s) to the pulse generator.
- The Lead: The pacing lead is an insulated wire that carries the electrical impulse to the heart and information about the heart's natural activity back to the pulse generator. One end of the lead is connected to the pulse generator at the connector block. The other end of the lead is usually inserted through a vein and placed in the right ventricle or the right atrium of the heart. One lead or two leads are used depending on the type of pacemaker prescribed by the physician.
HOW DOES A PACEMAKER FUNCTION?: There are two essential functions of a pacemaker: pacing and sensing. Pacing is when a pacemaker sends electrical impulses to your heat to start a heartbeat. The pacemaker paces the heart when the heart's own rhythm is interrupted, irregular or too slow. A pacemaker also has the ability to sense (monitor) the heart's natural electrical activity. If a pacemaker senses a natural heartbeat it will not pace the heart.
ARE THERE DIFFERENT TYPES OF PACEMAKERS?: Yes. Pacing therapy is diverse because the underlying heart conduction disorders that result in rhythm disturbances are different. The types of pacemakers available today are:
- Single Chamber Pacemakers
- Dual Chamber Pacemakers
- Rate Responsive Pacemakers
The type of pacemaker prescribed by a physician varies with the rhythm or conduction problem being treated and with the patient's lifestyle considerations.
HOW DO SINGLE CHAMBER PACEMAKERS FUNCTION?: A single chamber pacemaker typically uses one lead placed either in the right atrium or right ventricle to pace the heart. Single chamber pacing in the ventricle (lower chamber) is a common pacemaker therapy, and it is prescribed to treat a variety of conduction disorders.
Many patients are treated with atrial pacing. In this case, the lead is placed in the right atrium (upper chamber). The pacemaker then stimulates the atria to contract. The impulse continues to the ventricles to complete the heartbeat.
HOW DO DUAL CHAMBER PACEMAKERS FUNCTION?: Dual chamber pacemakers typically use two leads, one placed in the right atrium and the second one placed in the right ventricle. The electrical pulses delivered to the heart are timed so that the atria are stimulated to contract just before the ventricles. The timing ensures the atria and the ventricles are beating "in sync" with one another.
HOW DO RATE RESPONSIVE PACEMAKERS FUNCTION?: Your normal heart rhythm slows down or speeds up many times during the day. The heart beats slower while you are resting or sleeping. Exercise or emotional excitement require a greater amount of blood to be circulated and your heart beats faster. A rate responsive pacemaker use a special sensor(s) that recognizes body changes and helps the heartbeat speed up. Rate responsive pacemakers can be single chamber or dual chamber devices.
HOW CAN I LEARN MORE ABOUT THE HEART AND PACEMAKERS?: You physician or cardiology nurse are best suited to answer questions about your heart and pacemaker.
To save a lot of running around and traveling, yet to make sure the device is working properly, Community Medical Center offers a monitoring service for patients who have pacemakers. This service allows you to send an electrocardiogram (EKG) over the phone. An EKG is a written tracing of the heart's rhythm. This tracing is reviewed by a doctor who specializes in the care of those who have pacemakers. Much information can be obtained from the tracing. The tracing can determine if the pacemaker is pacing properly, if it is sensing the heart's natural beats properly, if the pacemaker is set to deliver enough energy and if the battery is getting low. All this is done by using a special device called a transtelephonic transmitter that is given to patents when they have a pacemaker implanted.
Keeping up with your telephone follow-up is very worthwhile!
