Do I need a pacemaker and, if so, what kind do I need?
A pacemaker stimulates the heart to beat and regulates the heart rate. In a normal heart, the sinoatrial (SA) node in the upper right chamber (atrium) spontaneously fires and stimulates the heart to beat. For this reason it is known as the pacemaker of the heart.
See an illustration of the heart and its electrical system
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In some heart diseases, the SA node may malfunction and fire very slowly or not at all. When this happens, the heart rate slows. Sometimes other parts of the heart will take over the pacemaker function if the SA node fails, although the heart rate generally remains slower than usual.
In other diseases, the SA node fires normally but the heart does not respond to its signals. This usually occurs because of disease in the electrical connections between the atria and the lower chambers (ventricles). This may prevent some or all of the electrical impulses generated by the SA node from being transmitted to the ventricles, a condition known as heart block.
If your heart rate slows down too much, either as a result of disease of the AV node or because of heart block, your blood pressure may fall, and you may experience fatigue, lightheadedness, palpitations, or dizziness, or you may temporarily lose consciousness. If this happens while you are standing, you may fall and injure yourself. If this occurs while driving, you can have a car accident. If a reversible cause of the slow heart rate cannot be identified, then an artificial pacemaker needs to be implanted.
What are the different types of pacemakers?
Cardiac pacemakers are implanted inside the body to regulate the heart's rhythm and prevent the heart from slowing down. Some of them only function in the bottom chamber of the heart (ventricle). Others work in the upper (atrium) and lower chambers.
What are temporary pacemakers?
Temporary pacemakers come in several forms. Typically, these pacemakers only are used until a permanent pacemaker is implanted. A wire can be placed through a vein and directly into the heart (transvenous pacing). Using this wire, an electrical impulse can be applied directly to the heart.
Temporary pacing can also be performed by using pads applied externally to the chest and an electrical shock delivered indirectly to the heart through the chest wall (transcutaneous pacing). This latter type of pacing requires a higher amount of electrical energy and can be somewhat uncomfortable. In some people, especially those who are obese, the transcutaneous pacemaker does not work well because of the increased amount of tissue between the skin and the heart. This type of pacing is only used in emergency situations, until another type of pacemaker can be placed.
| Author: | Robin Parks, MS | Last Updated: July 7, 2007 |
| Medical Review: | Adam Husney, MD - Family Medicine E. Gregory Thompson, MD - Internal Medicine Laurence Epstein, MD - Cardiac Electrophysiologist | |
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