Artificial Pacemaker

What is an artificial Pacemaker?

Artificial pacemakers are a two-part electrical system that includes a pulse generator (pacemaker) and one or two leads, or wires, which deliver impulses to the heart. The leads also carry signals back from the heart. By "reading" these signals, the pulse generator is able to monitor the heart's activity and respond appropriately. A pacemaker helps to pace the heart when the natural rate is too slow (bradycardia) to pump enough blood to the body.

Why Would I need an artificial Pacemaker?

Your heart is normally regulated by the heart's natural pacemaker. This natural pacemaker is called the SA (sino-atrial) node. The SA node automatically increases your heart rate in response to your body's needs -- for example, during exercise, when a faster heart rate is required. Sometimes, the SA node stops working properly. It may improperly speed up or slow down the rate at which it sends out electrical signals. If the signal rate is too slow, the chambers of the heart do not contract often enough to supply the proper amount of blood to your body.

What Is Heart Block?

Problems may also occur with the electrical pathway between the upper heart and the lower heart. The natural pacemaker signals sent out by the SA node may be delayed in the AV (atrioventricular node) or may fail altogether. This condition is called "heart block." Heart block often means that the ventricles pump too slowly even though the SA node may be sending out faster signals in an effort to increase the heart rate.

What Is a Pacemaker System?

Your artificial pacemaker alters your heart rate to help meet your body's needs. It does this by providing pacing signals that are much like the heart's normal signals. Depending on your particular situation, your pacemaker may:

* Replace the function of the heart's natural pacemaker or SA node. * Help maintain a normal timing sequence between the upper and lower heart. * Make sure critical lower chambers of the heart always contract at an adequate rate.

What makes up an artificial Pacemaker?

An artificial pacemaker is roughly the size of a silver dollar and about as thick as 2 silver dollars together. The pacemaker system is powered by a small battery sealed inside the pulse generator. The battery cannot be recharged. For this reason, the pulse generator must be replaced when the battery's energy is used up. The pacemaker also includes several electronic circuits. These circuits control the pacemaker's functions, including the way it monitors your heart's activity. Replacement of the device usually occurs in 4-8 years.

Artificial Pacemaker Types

There are two basic kinds of artificial pacemakers: single-chamber and dual-chamber. A single-chamber pacemaker has one lead to carry signals to and from one chamber of your heart --either the right atrium or the right ventricle. A dual-chamber pacemaker has two leads, with the tip of one lead positioned in the right atrium and the tip of the other lead located in the right ventricle.

How Is a Pacemaker Implanted?

The lead(s) are positioned in the right ventricle and also in the right atrium (when needed). A pocket is formed under the skin of the upper chest. The pacemaker is then connected to its leads. Most pacemaker surgery is done under local anesthesia. Additional medicine may be given in an IV to help the patient relax. The procedure typically takes 1 to 2 hours.

What Are the Complications?

All surgical procedures contain risks. These should be discussed with a physician.

What Happens After a Pacemaker Is Implanted?

Once the pacemaker is implanted, it is important that the patient be followed by a pacemaker clinic or a commercial group that specializes in pacemaker follow-up. The physician implanting the pacemaker should help the patient arrange appropriate follow-up. Pacemaker follow-up is usually done on a defined schedule. The schedule may vary depending on who is in charge of following or checking the pacemaker. Some physicians will prefer that the patient be seen in the office on a regular basis to have the pacemaker checked. Others will arrange a pacemaker check to be done by telephone, called transtelephonic monitoring, with periodic visits in the office or clinic. In many offices, the pacemaker check will be performed by a nurse or technician who is specially trained in management of pacemakers.

Pacemakers are checked with a special device called a programmer. A portion of the programmer is simply held over the pacemaker and is able to communicate with the pacemaker. It can obtain information about the function of the pacemaker. It can also change certain functions of the pacemaker to whatever the doctor, nurse, or technician feels is most appropriate. A special magnet may also be used during the pacemaker evaluation, and if transtelephonic monitoring is part of the follow-up, a magnet will probably be given to the patient to use during the telephone evaluations.

Frequently Asked Questions

1. How is the battery replaced in the artificial pacemaker? The battery is sealed inside the pacemaker case, or can, which also contains the electronic circuitry. When the battery's energy is depleted, a new pacemaker must be implanted. The surgery needed to remove the old pacemaker and implant the new one may require only a local anesthetic and is generally a very brief operation. In most cases, your original pacemaker lead(s) will not need to be replaced.

2. Is there a chance that my artificial pacemaker will fail? Yes, there is a remote possibility that any electronic device can fail, but technical advances in recent years have made it possible to make pacemakers very reliable.

3. What happens if my artificial pacemaker does fail? If your pacemaker should fail to function properly, you may experience the same symptoms that you had before you received the pacemaker. If you ever have these symptoms, contact you doctor as soon as possible.

4. Can I use my cellular phone? Yes. In certain cases, a cellular phone could affect your pacemaker's operation if it is closer to it than six inches. This interaction is temporary, and moving the phone away from the pacemaker will return it to proper function. To reduce the chance of interaction, maintain a distance of at least six inches between the cellular phone and your pacemaker; hold the cellular phone on the opposite side of your body from your pacemaker; do not carry a cellular phone in a breast pocket or on a belt if that places the phone within 6 inches of your pacemaker.

5. Will microwave ovens interfere with my artificial pacemaker? Microwave ovens will not interfere with pacemakers that are manufactured today or in recent years. Patients with pacemakers may use microwaves without concern.

6. Is there other electronic equipment that will interfere with my artificial pacemaker? Certain types of welding equipment could interfere with a pacemaker and should be discussed with your physician prior to using. There are other industrial sources of potential interference. If you work in an environment where heavy equipment is used, it is worthwhile discussing it with your physician to be certain there is no concern.

Certain types of hospital equipment may cause interference. MRI or magnetic resonance imaging equipment is capable of interference and is generally not performed in patients with pacemakers. MRI has been done in special circumstances in patients with pacemakers. If an MRI was felt to be critical, this would require discussion between you and the doctor ordering the MRI.

The text in this article is licensed under the Gnu Free it was taken from the artificial pacemaker article