Pacemaker

How a Pacemaker Works

A pacemaker is a two-part electrical system composed of a pulse generator and one or two leads that are surgically implanted under the skin in your chest, just beneath your collarbone. The pulse generator and the lithium battery that powers it are housed in a metal disc about the size of a man’s watch face. The pulse generator’s electronic circuitry continuously analyzes the heart’s rhythm and regulates the pacemaker function. The leads are thin insulated wires that are implanted inside the heart muscle in either the right atrium, the right ventricle or in both chambers. The leads receive electrical information from the heart and transmit electrical impulses that stimulate it to beat.

There are two types of pacemaker:

• Dual-chamber pacemakers use a lead in both the right atrium and the right ventricle, which enables the pulse generator to continuously regulate the heart’s electrical activity in both chambers to mimic the heart’s normal conduction pattern.
• Single-chamber pacemakers use one lead in either the right ventricle or the right atrium of your heart. A right ventricle lead is used when the electrical flow is slowed or blocked in the region of the atrio-ventricular (A-V) node—which transmits impulses to the left ventricle. A right atrium lead is commonly used in conditions where the sinus node—cells that act as the heart’s natural pacemaker—is not working adequately. It is used when the rest of the heart’s normal conduction system must be functioning normally.

Enlarge this Image

Living with a Pacemaker

Although your pacemaker may make you feel like a new woman, it also brings new responsibilities. Every couple of months you may need to check your pacemaker system over the telephone. You will be provided with a small monitoring device that is used to transmit your electrocardiogram over the telephone to a receiver station. This process monitors the battery life of the pulse generator and identifies any sensing or pacing abnormalities.

You may also have to exercise some caution around electronic devices. Although most security devices don’t interfere with pacemaker function, the metal case may set them off. Instead of walking through, you may want to show your pacemaker identification card and ask the guard to use the hand scanner. The anti-theft gates in department stores may emit electronic signals. It’s a good idea to pass through them quickly and not to linger near them.

Microwave ovens don’t pose any danger. Cell phones are also pretty safe, unless they are held over the heart. It may be a good idea to use an ear plug and keep the phone away from your chest while you are talking.