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Holter Monitoring & Event Recorders
Aug 21st 2008
Patients can develop symptoms related to
electrical disturbances from the heart (arrhythmias).
These symptoms can range from palpitations, weakness and dizziness, to chest
pain, shortness of breath or loss of consciousness. Your doctor may
need to do further cardiac testing to determine whether an electrical
disturbance is causing your symptoms. Two of the most common tests used
to investigate rhythm disturbances are Holter monitors and event monitors.
A
Holter monitor is a recording device that detects and records every heart beat
for a specified period of time, usually 24 -48 hours. The device has
electrodes attached to the chest much like an EKG. These are attached to
a portable recorder that is about the size of a beeper. This device is
usually worn continuously. It does not interfere significantly with
normal activity and patients are encouraged, in most cases, to perform their
usual activities or activities likely to cause their symptoms if not felt to be
dangerous. The device records the rhythm continuously. Patients usually
indicate when they are having symptoms by recording the time electronically and
in a diary that is provided. After the recording time is completed, all
the heart beats which represents a patient’s rhythm can be “downloaded” to a
computer and printed for review. The computer also can assist the
physician in analyzing the rhythm. This type of recorder is most useful in
patients that experience symptoms almost daily or have continuous rhythm
abnormalities such as atrial fibrillation.
An
event recorder is similar in that it also records a patient’s rhythm to a
recording device. It differs from a Holter monitor in that it will only
record the rhythm for a brief period of time, usually 30-60 seconds, and it
only records when it is activated by the patient during symptoms.
Although it may only record for 30-60 seconds for any single “event”, it can
record many such events and “store” them for review by the physician.
Event recorders are used more frequently in patients that only experience
symptoms occasionally. Patients may keep this recorder for as much as 1-2
months, usually until symptoms occur that are representative of the problem
being investigated. Patients are instructed in how to place the monitor
on and take it off. The more it is worn, however, the more likely it is
that an abnormal rhythm will be recorded, so patients are encouraged to wear
the device as much as possible. Even if symptoms are brief and gone
before the device is activated to record, patients are still told to activate
the recorder since most devices have a “memory” that actually records the
rhythm for a short period of time before patient activation. Most of
these recording devices allow a patient to “transmit” the recorded abnormality
over the phone to a center that can “download” it to a computer and print it
for review by your physician.
There are other ways rhythms abnormalities can be recorded including implanted
recording devices for long term recording. These can be analyzed with a
computer that “reads” the data through the skin using electromagnetic
signals. Most pacemakers and
defibrillators also record rhythm changes although the details available vary
between devices.
Which recording device is best in any situation depends on multiple factors
that will be determined by your physician.
Click here to learn more about holter monitoring.