What is a Pacemaker?
Your heartbeat is controlled by the heart's own bioelectrical
triggering system. When that system ceases to work properly, the solution
may be a pacemaker. A pacemaker is a small, battery-operated device that helps
the heart beat in a regular rhythm. It is used to replace a faulty natural
pacemaker or blocked pathway. There are two types of pacemakers, permanent
and temporary. Permanent pacemakers are called internal while the temporary
type is called external.
- A pacemaker uses batteries to send 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 have a sensing device that turns itself off when the heartbeat
is above a certain level. It turns back on when the heartbeat is too slow.
These are called demand pacemakers.
The pacemaker has two parts -- a battery-powered generator and the wires that
connect it to the heart. The silver-dollar-size generator, which has an effective
life of seven to 12 years, is implanted just beneath the skin below the collarbone.
The leads are threaded into position through veins leading back to the heart.
The entire implantation procedure requires only a local anesthetic, and takes
about an hour.
Most patients with pacemakers suffer from a condition in which the heart beats
too slowly (bradyarrhythmia). This is most commonly a result of deterioration
in the heart's own pacing system in elderly patients, though high blood pressure,
coronary artery disease or scarring from a heart attack can also cause bradyarrhythmias.
The most commonly installed pacing device is a demand pacemaker. It monitors
the heart's activity and takes control only when the heart rate falls below
a programmed minimum -- usually 60 beats per minute.
Other conditions which require pacemakers include heart block, in which the
heart stops beating altogether for several seconds and tachyarrhythmia, an overly
rapid heartbeat.
A more sophisticated type of pacemaker actually monitors a number of physical
changes in the body, which signal an increase or decrease in activity. If the
heart's own pacing system fails to respond properly, these rate-responsive pacemakers
slowly raise or lower the heartbeat to the appropriate level from 60 to 150
beats per minute.
If the patient's condition dictates reprogramming the implanted generator,
the cardiologist signals the changes to its tiny on-board computer with an electromagnetic
signaling device placed on the surface of the skin above the pacemaker.
Daily Living
Most patients are able to resume their normal daily activities after recovering
from surgery for a pacemaker. However, people with pacemakers need to be aware
of important recommendations and precautions about electricity and magnets.
Always tell any medical or dental personnel that you have a pacemaker. Guidelines
help you become aware of medical procedures that do, and do not, pose risks
to the proper functioning of your pacemaker.
When walking through airport and other security systems, people with a pacemaker
should be aware that certain security systems may detect the metal of their
device.
Being aware of these guidelines will help ensure your highest levels of comfort
and ease after receiving a pacemaker.
Myths
The warning signs posted advising pacemaker patients that a microwave oven
is installed is no longer necessary. Modern pacemakers are shielded from stray
electromagnetic forces and have a backup mode that takes over if a really strong
electromagnetic field disrupts the main circuit's programming.
