Holter monitor

cardiac diagnostic heart tests

What tests are available at London Heart Clinic?

Cardiac Diagnostic Tests 0:25
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General Heart Health FAQs

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Overview  |  Suitability  |  Preparation  |  The test  |  Restrictions  |  Risks  |  Results  |  FAQs


What is a Holter monitor?

We use a Holter monitor to record your heart activity outside our clinic. We also call this an ambulatory electrocardiogram (ECG) monitor. It is a compact, wearable device that records your heart’s electrical signals continuously for an extended period, typically 24 to 48 hours. Some people may need to wear them for 7 days to 2 weeks. Nowadays most of the devices we use are a small discreet patch without wires or attachments. 

This test allows us to gather valuable data on your heart rhythm and detect any irregularities or abnormalities we may not find during a short appointment. Ambulatory Holter monitors are useful for assessing heart conditions like arrhythmias, palpitations, fainting and other cardiac issues.  

By providing a detailed and continuous record of heart activity, they help us make accurate diagnoses and develop appropriate treatment plans.


Who needs a Holter monitor test?

We may recommend a Holter monitor if you experience palpitations, dizziness, fainting spells, unexplained chest pain, or have a history of heart disease, and a standard ECG hasn’t found the cause.

People with risk factors such as high or low blood pressure, diabetes, or a family history of cardiac issues may also benefit from Holter monitoring to detect potential problems early. If you have a pacemaker, we might also perform this test to assess how well it works.



We recommend wearing comfortable clothing, like a button-down or loose-fitting shirt, to make it easier to attach the monitor and electrodes to your chest. During the test, you will need to remove your top and, if you wear one, a wired bra. This is because the underwire may affect the reading. You may be able to keep wearing your bra if it is unwired or a sports bra. 

You will be given specific instructions about the patch. Avoid applying lotions, oils, or powders to your chest, as they can interfere with the electrode connections. Showering and exercising are fine, but we recommend avoiding bathing or swimming while wearing it.  

Let us know if you have any allergies, sensitive skin, or have experienced skin reactions previously. Lastly, carry a diary or notebook to record any symptoms or activities during the monitoring period, as this information can help us analyse your results. 


The test

First, you must remove your top and a wired bra if you wear one. We place electrodes (sticky patches with sensors and leads attached) on your chest that connect to a device you wear on your belt or a strap around your waist. The device is about the size of a mobile phone, so it should not feel uncomfortable to wear.  

We will ask you to clean your chest area first to make it easier for the electrodes to stick to your skin. Typically, we attach two or three leads to your chest, but we may use up to twelve. We may supply extra batteries depending on how long you need to wear the device. 

After the monitoring period, you will return the device to our office and share any notes you made about the symptoms you experienced. Our specialist can evaluate the readings from the test alongside your notes. 


Restrictions while wearing the device

After we have secured the device, we will discuss how long you need to wear it and what you can and cannot do with it. For example, you can work and perform usual household activities. When sleeping, we recommend finding a position on your back or side that will not affect the device or leads.


Risks and side effects

Holter monitors are safe and non-invasive with minimal risks. However, there are some potential considerations to be aware of. 

The most common risk is skin irritation or an allergic reaction to the adhesive patches we use to secure the electrodes on your chest. These can cause mild discomfort or skin redness, but it is usually temporary and easy to manage. It may look like a burn. 

In rare cases, some people may experience an allergic reaction to the materials used in the monitor itself. There is also a slight risk of infection at the electrode site if your specialist does not maintain proper hygiene during application, but this is rare. At London Heart Clinic, we ensure our specialists keep to the highest standards of care to avoid this and other complications. 

Follow our instructions for wearing and caring for the monitor to minimise these risks. Overall, the benefits of accurate cardiac monitoring typically outweigh these minor possible drawbacks.



Once we have reviewed your results, we will arrange an appointment to discuss them and plan our next steps. This test can help us identify whether you have a heart condition or allow us to assess any anti-arrhythmic medications you are taking. 

If you had abnormal results, we may recommend using an event recorder or wireless Holter monitor to record your heart rhythm for longer. An event recorder requires you to press a button when you experience heart symptoms, such as palpitations.

Abnormal results

The results can help diagnose arrhythmias, such as atrial fibrillation, premature ventricular contractions (PVCs), ventricular tachycardia (fast heart rate) and bradycardia (slow heart rate). We can also detect silent myocardial ischaemia episodes.


Book a private Holter monitor

Book a private Holter monitor test with us and gain valuable insights into your heart’s rhythm and function. Our experienced team provides a seamless and comfortable monitoring experience. We are also able to arrange for the monitor to be delivered to you if you are unable to attend the clinic.

Whether you’ve been experiencing symptoms or simply want to ensure your heart is in peak health, this proactive step can make all the difference

Contact us now to schedule your test and prioritise your cardiovascular health.

Dr Syed

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Get in touch or book an appointment to discuss how London Heart Clinic could help.

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Frequently asked questions

    At London Heart Clinic, this test starts from £295 but the costs can vary depending on the length of time your heart needs monitoring.

    No, we may recommend this test to determine whether your heart is still experiencing problems with no noticeable symptoms after treatment.

    No, the ambulatory Holter monitor test should not hurt, though you may experience some discomfort at the electrode sites.

What our patients say

“After suffering from a heart condition for a number of years I was very happy to meet Dr Ahsan, from the first consultation where he believed there was a solution I have now completed the surgery and had my final consultation with him today…”


“I am very grateful to have Dr Syed Ahsan as my consultant. Dr Ahsan always greets you warmly on each visit despite his busy workload. Dr Ahsan explains everything clearly and helps you to understand even the most complex medical terms…”


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