A Holter monitor is a small device that's used to check the heart's rhythm over time. A Holter monitor is worn, usually for 24 to 48 hours. The monitor isn't very big, it's about the size of a postcard, and wearing the monitor isn't painful.
A Holter heart monitor is used to complete an ambulatory electrocardiogram (ECG), this just means that you can go about most normal activities while your heart is being monitored. There isn't any electricity being sent into your body during an electrocardiogram (including a Holter monitor), your doctor just wants to monitor the electrical activity that your heart naturally produces.
A patient may need a Holter monitor to check for cardiac arrhythmias, heart palpitations, because they have experienced chest pain, shortness of breath, dizziness, or fainting. Or to check for the risk of future cardiac issues. Holter monitors are also sometimes used to see how well a certain treatment is working.
Before the test
There's usually no preparation necessary for a Holter monitor. Based on the patient's condition, sometimes doctors will ask for a specific preparation.
During the test
The Holter monitor can be stored in a pocket or a pouch worn around the neck during the test. It will record your heart's electrical activity while it's worn. You'll be given a diary to write in while you're wearing the monitor, make sure to write down your activities and any symptoms you experience during that time. Examples of symptoms that you should write down include dizziness, palpitations, and chest pain. If there are any symptoms that you or your doctor are concerned about, then you should make a note of those as well. Be sure to give this diary to your doctor when you return the Holter monitor, it'll help your doctor to understand the results of the test.
If you have experienced certain symptoms while exercising, your doctor may ask you to exercise while wearing the Holter monitor. Certain conditions only produce symptoms when the heart is beating faster than normal, so the Holter monitor is used to help your doctor better understand your heart.
There aren't any significant risks associated with wearing a Holter monitor. Sometimes patients, at the spots at which the electrodes were placed, experience discomfort or skin irritation.
If the Holter monitor gets wet, it will be damaged, so don't shower or take a bath while wearing the Holter monitor (which is usually just one or two days). Try to keep certain electrical appliances away from the monitor, such as metal detectors, magnets, electric blankets and electric razors, and cellphones. These devices can sometimes affect the signal from the electrodes to the monitor.
After the test
Once you've returned to the doctor's office and had the Holter monitor removed (as well as giving your doctor the diary), your doctor will evaluate the results. Once he or she has done so, your doctor will talk to you about your health. Your doctor may be able to diagnose what's causing your symptoms based on the results of the Holter monitor, sometimes they'll want further testing, like an implantable loop recorder or wireless Holter monitor.