Arrhythmia Testing: What Is A Holter Monitor, And What To Expect?

Making the correct diagnosis can be tricky for doctors. Many diseases and conditions share symptoms, signs, and risk factors, after all, and this is especially true when it comes to afflictions of the heart. 

What is this so-called ‘Holter monitor’?

A Holter monitor is a small device that you carry around in your pocket or around your waist (or anywhere else that’s convenient). It monitors your heart’s activity through five small electrodes (patches that conduct electricity) that are placed on your chest and connect to the monitor through wires. Using these electrodes and wires, a Holter monitor can measure your heart’s electrical activity.

Why would I use a Holter monitor, and how does it work?

You might have assumed that your doctor could make a diagnosis at the hospital, using the equipment there, and that there’d be no need to carry a device around with you. However, it’s not so simple.

The electrodes placed on your chest (near your heart) allow the device to pick up your heart’s electrical activity. The heart’s electrical system determines how it beats, and how blood flows through it. Thus, many different heart conditions and arrhythmias are related to problems with the heart’s electrical system, making Holter monitors ideal for discovering these types of issues. As the Holter monitor collects information about your heart’s electrical activity, it also records — making data available to your doctor 24 to 48 hours later. 

Are there any risks I should be aware of when I wear a Holter monitor? 

Using a Holter monitor doesn’t come with any significant risks. There is a small chance that the adhesive used to attach the wires to your skin can cause an allergic reaction, but the effects will wear off as soon as the patches are removed. 

When you use a Holter monitor, you should go about your day as you usually do, keeping the device somewhere secure. However, you can’t take a bath or shower with a Holter monitor. Your doctor will probably give you a diary to record your symptoms and the time during which they strike. This will allow your doctor to compare your symptoms to the Holter monitor’s results.

What kind of conditions could a Holter monitor discover? 

A Holter monitor can be used to assess the damage of a heart attack or to find out how a newly-prescribed medicine affects your heart. However, abnormal results most frequently signal that you have an arrhythmia, a condition that causes a fast, slow, or irregular heartbeat. 

What other tools can detect heart abnormalities?

An event monitor is like a Holter monitor, except it uses two wires rather than five, and can be removed for bathing and reattached later. Patients may wear these devices for several months, and instead of recording 24/7, you can activate them yourself when you notice symptoms. 

Loop recorders are for even more infrequent symptoms, as they can last for years. Unlike the former two, loop recorders are implanted into the chest, where they may record automatically or when patients activate them.

Two other tests are done in a hospital or doctor’s office for infrequent arrhythmias.

The first is an electrophysiology study (EPS), in which electrodes inserted through the neck or groin are used. Unlike an ECG, an EPS analyzes the heart’s electrical activity from as close to the heart as possible. It’s used to pinpoint existing arrhythmias, deciding what the best treatment is, and determining future risk. 

A stress test, on the other hand, is far less invasive. Whereas some heart conditions are periodic, others only occur during strenuous physical activity. During a stress test, you’ll be asked to exercise while a doctor measures heart rate, blood pressure, and the heart’s electrical activity. A doctor will try to make sure this test is as safe as possible for those whose heart may not be as healthy.