When symptoms such as dizziness, fainting, low blood pressure, prolonged fatigue, or palpitations continue to occur without a definitive diagnosis obtained with a resting electrocardiogram (ECG), your physician may request an ECG tracing to be run over a long period of time. Certain arrhythmias (a fast, slow, or irregular heartbeat) which can cause the symptoms noted above may occur only sporadically, or may occur only under certain conditions, such as stress. Arrhythmias of this type are difficult to obtain on an ECG tracing that only runs for a few minutes.

A prolonged type of ECG tracing, called a Holter Monitor, provides the physician a better opportunity to capture any abnormal heartbeats or rhythms that may be causing your symptoms.

The Holter Monitor test is used to record your ECG tracing continuously for a period of 24 hours or longer. You will receive instructions on how long you will wear the recorder (usually 24 hours, but sometimes longer), how to keep a diary of your activities and symptoms during the test, and personal care/activity instructions.

Event Monitoring is very similar to Holter Monitoring, and is often performed for the same reasons. With an Event Monitor, you wear ECG electrode patches on your chest, and the electrodes are connected by wire leads to a recording device. However, unlike the Holter Monitor, which records continuously throughout the testing period of 24 to 48 hours, the Event Monitor does not record until you feel symptoms and you trigger the monitor to record the ECG tracing at that time.

When you feel one or more symptoms, such as chest pain, dizziness, or palpitations, push a button on the Event Monitor recorder. Some monitors have a feature called "memory loop recording," in which the monitor can include a recording of a short period of time prior to the moment you triggered the recording and afterwards. This feature can help your physician determine more details about the possible change in your EKG at the time the symptoms started, and what was happening with your EKG just before you or triggered the recorder. Other monitors, called "Post-Event Recorders," simply start recording the EKG from the moment you trigger it.

After symptoms are experienced and recorded, you will send the recording to your physician or to a central monitoring center. You will also keep a diary of your symptoms and corresponding activities, just as with the Holter Monitoring procedure.

Why is Holter or Event Monitoring used?

Some reasons for your physician to request a Holter Monitor procedure include, but are not limited to, the following:

• to evaluate chest pain
  
  

• to evaluate other signs and symptoms which may be heart-related, such as fatigue, shortness of breath, dizziness, or fainting
  
  

• to help identify irregular beats
  
  

• to further evaluate arrhythmias noted on a resting ECG

How is the Holter Monitor procedure performed?

The following steps provide information regarding how a Holter Monitor procedure is performed:

• ECG electrodes will be placed on your chest, and the ECG monitor will be attached to the electrodes with lead wires.
  
  

• The ECG monitor is small and portable - about the size of a paperback book. The monitor may have a shoulder strap so that the monitor box may be worn over the shoulder like a shoulder bag, or it may clip to a belt or pocket.
  
  

• You will be given instructions regarding:
  
  

  • how to keep the electrodes attached to your skin.
    
    

  • how to check the monitor for problems.
    
    

  • when to call the physician's office for help.
    
    

  • keeping the electrodes and monitor dry by not allowing you to take a shower or tub bath (a sponge bath is usually allowed) or go swimming.
    
    

  • avoiding situations where your may perspire excessively, causing the leads to detach.
    
    

  • how to keep a diary during the procedure, noting the date and time of day of any changes in activity and symptoms your experiences.
    
    

  • avoiding using electrical appliances such as electric razors, hair dryers, or electric toothbrushes near your child so that the EKG signal will not receive electrical interference on the recording tape. If these appliances must be used, you should note it in the diary.
    
    

  • avoiding magnets, metal detectors, areas with high-voltage electrical wires, and electric blankets during the procedure, since they can also create electrical interference on the recording tape.
    
    

• Once you have been hooked up to the monitor and you have been given instructions, you will be allowed to return to your usual activities, unless the physician instructs you otherwise.
  
  

• You will be given a telephone number to call in case one or more of the electrodes comes off or if the monitor starts beeping.
  
  

• Be sure to write down the date and time of any symptoms your experiences in the diary, as well as what you were doing at the time and any unusual circumstances that were also present.
  
  

• At the end of the procedure, you will return to the physician's office to have the electrodes removed and the monitor discontinued. Alternatively, you may be instructed to do this yourself at a certain time and date.

Depending on the results of the Holter Monitor, additional tests or procedures may be scheduled to gather further diagnostic information.