What To Expect When Using a Holter or Event Monitor

Your experience while using a Holter or event monitor depends on the type of monitor you have. However, most monitors have some factors in common.

Recording the Heart’s Electrical Activity

All monitors record the heart’s electrical activity. So, it’s important to maintain a clear signal between the sensors (electrodes) and the recording device.

In most cases, the sensors are attached to your chest with sticky patches. Wires connect the sensors to the monitor. You usually can clip the monitor to your belt or carry it in your pocket. (Postevent and implantable loop recorders don’t have chest sensors.)

Holter or Event Monitor

Figure A shows how a Holter or event monitor attaches to a patient. In this example, the monitor is clipped to the patient’s belt and electrodes are attached to his chest. Figure B shows an electrocardiogram strip, which maps the data from the Holter or event monitor.

A good stick between the patches and your skin helps provide a clear signal. Poor contact leads to a poor recording, which is hard for your doctor to read.

Oil, too much sweat, and hair can keep the patches from sticking to your skin. You may need to shave the area where your doctor will attach each patch. You will need to clean the area with a special prep pad that your doctor provides.

You may need to use a small amount of special paste or gel to make the patches stick to your skin better. Some patches come with paste or gel on them.

Too much movement can pull the patches away from the skin or create “noise” on the rhythm strip. A rhythm strip is a graph showing the pattern of the heartbeat. Noise looks like a lot of jagged lines and makes it hard for the doctor to see the real rhythm of the heart.

When you have a symptom, stop what you’re doing. This way you can be sure that the recording shows the heart’s activity rather than your movement.

Your doctor will tell you whether you need to adjust your activity level during the testing period. If you exercise, choose a cool location to avoid sweating too much. This will help the patches stay sticky.

Other everyday items also can disrupt the signal between the sensors and the monitor. These items include magnets, metal detectors, microwave ovens, and electric blankets, toothbrushes, and razors. Avoid using these items. Also avoid areas with high voltage.

Cell phones and iPods may interfere with the signal if they’re too close to the monitor. When using any electronic device, try to keep it at least 6 inches away from the monitor.

Keeping a Diary

When using a Holter or event monitor, you need to keep a diary of your symptoms and activities. Write down when symptoms occur, what they are, and what you were doing at the time.

The most common symptoms of heart rhythm problems include:

• Palpitations. This is the feeling that your heart is pounding, racing, fluttering, or beating unevenly.
• Fainting or feeling dizzy.

It’s important to note the time symptoms occur, because your doctor matches the data with the information in your diary. This allows your doctor to see whether certain activities trigger changes in your heart rate and rhythm.

You also should include details in your diary about when you take any medicine or if you feel stress at certain times during the test.

What To Expect With Specific Monitors

Holter Monitor

The Holter monitor is about the size of a large deck of cards. You wear it for 24 to 48 hours. When the test is complete, you return the device to your doctor’s office. The results are stored on the device.

You can’t get the monitor wet, so you won’t be able to bathe or shower. You can take a sponge bath if needed.

The recording period for a standard Holter monitor may be too short to capture a heart rhythm problem. If this is the case, you may need a wireless Holter monitor.

Wireless Holter Monitors

Wireless Holter monitors can record for a longer time than standard Holter monitors. A wireless monitor records for a preset amount of time. It then automatically sends data from the monitor to your doctor’s office.

These monitors are called wireless because they use a cell phone to send the data to your doctor’s office. They still have wires that connect the device to the sensors stuck to your chest.

You can use a wireless Holter monitor for days or even weeks until signs or symptoms of a heart rhythm problem occur.

The batteries in the wireless monitor must be changed every 1 to 2 days. You will need to detach the sensors to shower or bathe and then reattach them.

Event Monitors

Event monitors are slightly smaller than Holter monitors. Event monitors record heart rhythm problems when you activate them. They can be worn for weeks or until symptoms occur.

Most event monitors are worn like Holter monitors—clipped to a belt or carried in a pocket. When you have symptoms, you simply push a button to start recording.

Postevent Recorders

Postevent recorders may be worn like a wristwatch or carried in a pocket. The pocket version is about the size of a thick credit card. These recorders don’t have wires that connect the device to chest sensors.

To start the recorder when you feel a symptom, you hold it to your chest. To start the wristwatch version, you touch a button on the side of the watch.

You send the stored data to your doctor’s office using a telephone. Your doctor will explain how to use the monitor before you leave the office.

Autodetect Recorders

Autodetect recorders are about the size of the palm of your hand. Wires connect the device to sensors on your chest.

You don’t need to start an autodetect recorder. This type of monitor automatically starts recording when it detects an abnormal heart rhythm. It then sends the data to your doctor’s office.

Implantable Loop Recorders

Implantable loop recorders are about the size of a pack of gum. This type of event monitor is inserted under the skin on your chest. No chest sensors are used.

The device records either when you activate it or automatically when symptoms occur. It depends on how your doctor programs it. Devices may differ, so your doctor will tell you how to use it. In some cases, a special card is held close to the recorder to start it.