Monitors

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Holter Monitors

A Holter monitor is a device which is capable of recording your heart rhythm onto a tape or memory card over a period of 24 hours.

A Holter monitor could be ordered by your physician in order to:
  1. Evaluate symptoms of palpitations, dizziness, or lightheadedness when an arrhythmia is the suspected cause 

  2. Evaluate the effect of a drug on treatment of an arrhythmia 

  3. Evaluate the function of an existing implanted pacemaker 

  4. Evaluate the frequency of arrhythmia in someone with an implantable cardioverter defibrillator (ICD)

The Holter monitor consists of a base unit about the size of a portable tape cassette player and a set of five wires (leads). The leads are attached to the patient using sticky patches (electrodes). The patient wears the Holter monitor around during their daily activities while it records the heart rhythm for a period of 24 hours. Upon returning the Holter monitor, the tape is scanned into a computer and checked for accuracy. A report is then produced detailing the heart rhythm analysis which includes:
  • the minimum, maximum, and average heart rates
  • the number of extra beats from the upper chamber of the heart (APCs) 
  • the number of extra beats from the lower chamber of the heart (VPCs) 
  • the number of times the heart pauses for more than 2 seconds 
  • the number, length, and rate of runs of arrhythmia (SVT) originating in the upper chambers of the heart (atria) 
  • the number, length, and rate of runs of arrhythmia (VT) originating in the lower chambers of the heart (ventricles)

A patient log of symptoms is recommended during the 24 hour recording period. This enables the physician to correlate any symptoms with any arrhythmia noted on the Holter recording.

Important Tips

  • Please call the office prior to coming in to have a Holter monitor attached to ensure we have one available in the office
  • Do NOT take a shower or bath while you are wearing the Holter monitor - this will ruin the device
  • Do  NOT detach then attempt to reattach the Holter monitor - this could potentially make most or part of the recording useless
  • Please return to the office about 24 hours after the Holter was attached to have us remove it
  • If you cannot come back to the office the following day to have the Holter monitor removed please let us know so that we can show you how to remove the monitor yourself and also make arrangements to get the monitor back to our office

We should have the results of the monitor available within 48-72 hours after we receive the tape - if there is a serious abnormality detected we will contact you immediately. If you wish to know the results prior to your next office visit please call the office and leave us a message and we will call you back with the results as soon as we are able.

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Event Monitors

An event monitor is a device which is also capable of recording your heart rhythm but which does so without the use of attached wires. The device itself is small, about the size of a deck of cards (or smaller). On the back side of the device are metal electrodes, which when held against the skin, are capable of recording the heart rhythm.

An event monitor is usually ordered by your physician to evaluate intermittent symptoms of palpitations, dizziness, or lightheadedness when an arrhythmia is the suspected cause and when loss or impairment of consiousness is not an issue. This device might be employed if a Holter monitor recording does not elucidate the cause of symptoms. Since arrhythmias can sometimes be intermittent, a single 24 hour Holter recording or even many 24 hour Holter recordings might not be adequate to capture the arrhythmia.

The device is small enough to be carried around in a pocket or purse until a symptom is noticed. The device can then be placed against the skin (usually on the chest wall close to the heart) and a button pressed to record the heart rhythm. When finished, the rhythm can then be transferred via the telephone to a station where it is printed on paper and faxed to your physician.

This device can be very helpful in correlating an arrhythmia with a symptom. The device itself is small so it can be carried almost anywhere, and since it is not attached to the patient, can be used for weeks at a time without much inconvenience. The drawback of the device is that the symptom needs to be of sufficient duration to enable the patient to locate the device and get to an area where they can record their heart rhythm.

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Loop Recorders

A loop recorder is a device which is capable of recording your heart rhythm for small periods of time. It attaches to the patient with wires (leads) like a Holter monitor but is typically much smaller and uses a fewer number of leads. It can be removed for periods of time to enable the patient to shower or bathe and can be reattached by the patient.

A loop recorder is usually ordered by your physician to evaluate intermittent and/or brief symptoms of palpitations, dizziness, or lightheadedness when an arrhythmia is the suspected cause. This device is preferred over an event monitor when loss or impairment of consciousness might be an issue and/or when symptoms are of brief duration. This device might be employed if a Holter monitor recording does not elucidate the cause of symptoms. Since arrhythmias can sometimes be intermittent, a single 24 hour Holter recording or even many 24 hour Holter recordings might not be adequate to capture the arrhythmia.

The loop recorder works by continuously recording your heart rhythm onto a memory chip. When you have a symptom, pressing the button on the device freezes the previously recorded information and continues to record and store your heart rhythm. The amount of time of your heart rhythm that the device stores before and after the button is pressed is usually programmable but is typically 30 seconds and 1 minute, respectively. When finished, the rhythm can then be transferred via the telephone to a station where it is printed on paper and faxed to your physician.

This device can be very helpful in correlating an arrhythmia with a symptom. The device itself is smaller than a Holter monitor and the leads can be removed and replaced by the patient so it can typically be used for weeks at a time with minimal inconvenience. The drawback of the device is that it does need to be attached to the patient and can therefore be inconvenient to use for long periods of time.

There is also an implantable loop recorder (Reveal Plus, Medtronic Inc.) available which is similar in function to the external loop recorders except that it is implanted underneath the patient's skin. This device is typically used in patients who are passing out (syncope) infrequently without a clear cause for the episodes. The device can be activated by the patient after they regain consciousness or can be set to activate itself for very slow or fast heart rhythms. It can then be interrogated through the skin by their physician at a later time. When the cause of the syncopal episodes is finally elucidated, the device can then be removed and appropriate treatment can be initiated. The battery in these devices usually lasts between 12 and 14 months. Click here to see an image of an implantable loop recorder.

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