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Ambulatory electrocardiography (EKG
or ECG) monitors the electrical activity of your heart while you go
about your usual daily activities. Many heart problems occur only
during certain activities, such as exercise, eating, emotional
stress, or sleeping. A continuous 24-hour recording is much more
likely to detect any abnormal heartbeats that occur during these
activities.
Holter monitoring
The most common type of ambulatory
monitoring is called Holter monitoring. The recording device of a
Holter monitor is worn on a strap at your waist or over your
shoulder. The electrical signals of the heart are picked up by two
electrodes attached to your chest, which are connected to the
recorder by wires. Holter monitoring provides a continuous 24- to
72-hour record of the electrical signals from your heart. While
wearing the Holter monitor, you will also be asked to keep a journal
of your activities and symptoms each day. After the monitoring
period, your doctor will compare the timing of your activities and
symptoms with the recorded heart pattern.
Many people have irregular
heartbeats, or arrhythmias, periodically. The significance of
irregular heartbeats depends on the type of pattern they produce,
how frequently they occur, their duration, and whether they occur
simultaneously with symptoms reported. Because arrhythmias can occur
irregularly, it may be difficult to record one while you are in the
office. A standard EKG monitors only 40 to 50 heartbeats during the
brief period you are monitored by the machine. A Holter monitor
records about 100,000 heartbeats in 24 hours and is much more likely
to detect a problem.
Cardiac event monitoring
Another kind of ambulatory EKG
monitoring is called cardiac event monitoring. This can be used when
symptoms of an abnormal heart rhythm occur infrequently. A cardiac
event monitor can be used for a longer time than a Holter monitor
and is more likely to record an abnormal heart rhythm that occurs
less frequently. The information recorded by a cardiac event monitor
is sent over the phone to our office.
Why is Holter/Event Recording Done?
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Detecting arrhythmias that occur
intermittently or during certain activities.
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Evaluating symptoms of possible
heart disease such as chest pain, palpitations, dizziness, or
fainting.
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Detecting poor blood flow to your
heart muscle (ischemia), which may indicate coronary artery
disease (CAD).
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Monitoring the effectiveness of
treatment, such as medication or a pacemaker for abnormal heart
rhythms.
How To Prepare
It
is a good idea to shower or bathe prior to using a Holter monitor,
because you will not be able to do so during the recording period.
Wear a loose-fitting blouse or shirt.
How It Is Done
Holter monitoring
For Holter monitoring, a
lightweight, battery-operated tape recorder (monitor) is worn on a
strap over your shoulder or around your waist. The monitor is
connected by wires to electrodes taped to your chest. The electrodes
detect the electrical signals from your heart. A Holter monitor also
has a clock linked to the recorder so you can write down what time
it is when symptoms occur.
Our technician will fit you with the
monitor and electrodes. Several areas on your chest may be shaved
and cleaned, and then a small amount of electrode gel will be
applied to those areas. Several electrode pads will then be attached
to your chest, with thin wires connecting the electrodes to the
monitor. You will also receive a booklet to write down any symptoms
you have during the monitoring period, including the type of
activity you were engaging in and the time your symptoms occurred.
You then resume normal daily
activities while wearing the monitor. In the journal, write down the
exact times when you exercise, climb stairs, eat, urinate, smoke
cigarettes, sleep, get emotionally upset, take medications, or
engage in other activities. If you have any symptoms of heart
problems, i.e. dizziness, fainting, chest pain, or palpitations,
push the event-marker button on the Holter monitor to mark it and
write down the exact time and duration of the symptom. For example,
you might write: "12:30 p.m. Ate lunch. 1:00 p.m.
Argument with boss, had chest tightness for several minutes." The
accuracy and effectiveness of this test depends on how carefully you
record your activities and symptoms and the times they occurred.
Overnight, try to stay on your back
with the recorder carefully positioned at your side to ensure that
the electrodes are not pulled off. If one of the electrodes or lead
wires becomes loose, a light on the monitor will flash. Press on the
center of each electrode to see if you can restore the contact. If
one of the electrodes comes off and you have difficulty replacing
it, call us.
At the end of the recording period
(usually 24 hours), you will either return to the office to have the
electrodes removed or, if you've been taught how, you may remove the
electrodes yourself. A computer will analyze the recorded tape to
provide information about your heart rate, the frequency of heart
beats, and any abnormalities.
Cardiac event monitoring
The procedure for cardiac event
monitoring depends on the type of monitor used.
Electrodes will be attached to your
chest in the same way as a Holter monitor, and you will be
instructed to start the recorder when you have symptoms of a heart
problem.
How It Feels
The sites where the electrodes are
on the chest may itch slightly during the recording, and the skin
may become slightly irritated when the electrodes are removed. The
recording unit is very lightweight, so carrying it usually is not
problematic.
Risks
There is no risk associated with
Holter or event monitoring. The electrodes placed on your skin only
detect the electrical signals from your heart. No electricity is
sent through your body, and there is no possibility of receiving an
electric shock.
Results
Results of ambulatory
electrocardiography monitoring are interpreted by our cardiologists.
The results are generally available in a few days.
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