Event Monitor


An Event Monitor is a form of ambulatory monitoring. Electrodes are attached to your chest and then attached into a battery powered device usually carried in your pocket, or worn on a belt. An event monitor is similar to a Holter monitor. However an event monitor measures electrical conductivity of your heart for a period of a week or more. It differs from a Holter monitor because you have to signal when you feel symptoms in order for the device to record electrical conductivity from your heart. The event monitor attaches the same way a Holter monitor does. There are three wires (leads) which are attached from your chest to a pager like device that you carry around. There will most likely also be a different device in which you have to input when you feel symptoms. The symptoms are usually preprogrammed and include feelings of dizziness, lightheadedness, chest pain, and palpitations. The device also requests for you to notify what activities you are performing at the time of your symptoms. Periodically, sample rhythms are recorded and sent to your doctor without activating the recording. It is important for you as a patient to be proactive into input the activity you are performing and the symptoms you felt at the time you request the device to record. This helps your Doctor determine if the symptoms you are feeling correlate with any abnormalities found on the event monitor.

Why Performed

When a patient has relatively frequent symptoms (once a week to once a month) that may be related to alterations in the electrical conductivity of the heart, an Event monitor may prove useful. One of the most common symptoms to obtain an Event monitor is palpitations. If you do not normally have symptoms at least once a month, then an Event monitor is probably not the best test for you (on most occasions).   However, sometimes an event monitor may prove useful if you have symptoms on the magnitude of once every 2 to 3 months. Your doctor may order the event monitor to determine if you have lesser forms of the rhythms of concern. Sometimes multiply that monitors may be performed in order to catch the abnormalities in your electrical system that are causing your symptoms.

Other common symptoms in which an Event monitor may prove useful, may be:

  • dizziness
  • passing out (syncope)
  • fatigue
  • atrial fibrillation
  • atrial flutter
  • chest pain
  • shortness of breath

This is not an all-inclusive list, but are the most common reasons for obtaining an Event monitor. Sometime, your doctor may order an Event monitor to determine if treatment has been effective and if you have resolved your irregular rhythms. This is especially true in patients with atrial fibrillation or atrial flutter, once a treatment has been initiated. Some patients with ventricular tachycardia are placed on medicines and an event monitor is used in order to assure that this rhythm has been resolved with treatment.


There are not many risks associated with the Event monitor. They are similar to obtaining an electrocardiogram. Mostly, the only risk is usually related to reactions to the adhesive tape of the electrodes (adhesive tape-like component that is placed on skin).


Not much preparation is required to have an Event monitor performed. Be prepared to have clean skin before applying the electrodes (adhesive tape-like component that is placed on skin) to your chest wall. You might have to shave your chest at specific locations where the electrodes are placed in order to assure contact with the skin. Sometimes electrodes fall off, but this is not a problem since most devices arrived with multiple sets of adhesive electrodes. You should be ready to where your Event monitor as long as you may tolerate it and only take it off to shower. Please have multiple batteries (usually AA) ready and with you in case your device runs out of charge.


For an Event monitor, you should expect the device to either be attached to you in the cardiologist’s office or sent to you by mail. If it is sent to you by mail, there will be instructions on how to place the electrodes (adhesive tape-like component that is placed on skin) and where to connect the leads. If you have questions please call your cardiologist’s office. The duration of Event monitoring will most likely be 1-4 weeks depending on your Doctor’s order. When you have completed your monitoring you will either pack up the Event monitor and send it via mail, or take it to your cardiologist’s office. You should receive results in approximately 2 to 3 days after the device has been received and the data downloaded. It is important to remember log the symptoms and activity while wearing the Event monitor, to determine if your symptoms correlate with any abnormalities found on the Event monitor. This helps your Doctor determine if any abnormalities found on your Event Monitor are causing the symptoms your are feeling.


Results are usually ready two to three days after the device has been received and data analyzed. In it you will find your basic heart rhythm with any alterations, extra beats, irregular rhythms, highest and lowest heart rates, length of time spent in each irregular rhythm, and any other abnormalities associated with your heart rhythm. Your results will discover relatively benign rhythms such as atrial fibrillation, atrial flutter, supraventricular tachycardia or malignant rhythms such as ventricular tachycardia. Commonly, there are extra beats discovered such as premature ventricular contractions (PVC) or premature atrial contractions (PAC).