Expert London Cardiologist for your Heart Health

68 Harley Street

London, W1G 7HE
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Cromwell Hospital, Syon Clinic
Bishops Wood

0203 9838 001

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Ambulatory ECG

6 ways of performing Ambulatory ECG or Holter Monitoring
Palpitations can be a sign of arrhythmia

A static ECG shows your heart’s activity as a snapshot and so it can miss palpitations that come and go.  

Getting a recording of the heart, using Holter Monitorting, at the time of symptoms, is absolutely key to diagnosing a cardiac arrhythmia.

Holter monitors or ambulatory Electrocardiograms (‘ECG’) help diagnose palpitations and cardiac arrhythmia.

This is an ECG test that records information for a longer period than a standard resting ECG. Those tests only record the heart electrical activity for a 6 second snap shot. In contrast, a Holter monitor can record the ECG over 24, 48 or 72 hours. 

You wear under your clothes and continue with your day to day activities.  This is a way of monitoring your heart rate throughout the time that you wear the device.  When analysed, Cardiologists can identify your  underlying heart rhythm and detect any episodes of arrhythmia.  Knowing your exact underlying arrhythmia is essential as it determines your treatment and identifies your individual risk.

“Wearing a ‘Holter’ monitor at the time of symptoms can really simplify making a patient’s diagnosis.  We can also use it to monitor the impact of treatment.”

The Test Procedure

Our technician will fit you with the Holter monitor.  This will involve placing sticky electrodes onto the chest and connecting ‘leads’ or small wires to these.  You may be asked to wear the monitor for 24 hours or even longer depending on your condition.  

Continue with all your normal activities on the day of the monitor.  Make a note of the times you have your symptoms – being precise helps make a better diagnosis and will help you most.

If you need to wear the monitor for a period longer than 24 hours, ask the technician to show you how to remove and replace the electrodes and leads. Its fairly simple but getting it right will improve the accuracy of the reading. 


The Test Procedure

Getting the Results

Dr Nijjer will analyse the data and look throughout the recording.  We pay specific attention to the times you had your symptoms so don’t forget to note these times down.

Dr Nijjer’s team will then arrange a time to discuss the findings and make a plan for your treatment.


ZioPatch with Patient Activation

Advanced ECG monitoring: Patient Activated Recorders

In some cases, Dr Nijjer will recommend a Patient Activated Recorder. This is very similar to other Holter monitors but it comes with a handheld trigger unit. You, as the patient, can press the button on the device which then activates the monitoring system. This can be really helpful when we need to correlate your symptoms more closely with changes on the recorded ECG. 


ZioPatch and Prolonged Monitoring

Traditional Holter monitors involve a number of stickers with leads or wires stuck to the chest. This can be incredibly useful as we can record 3 different ECG traces of the heart but is limited by discomfort. It is difficult to wear a traditional Holter monitor for a prolonged period of time. If palpitations only occur once or twice a week, it can mean that we can miss your symptoms on the recording.

A solution is the ZioPatch. This is a small and unobtrusive monitor that sticks physically to the skin. The adhesive is strong and generally well tolerated by patients. It is strong enough to tolerate showering and even swimming. The monitor can remain on the skin for up to 14 days and this means we are much more likely to capture the arrhythmia and make the correct diagnosis. Studies have shown that ZioPatch monitors and prolonged monitoring provide more diagnoses and treatment decisions compared to traditional Holter monitors. 


ZioPatch Monitoring
ZioPatch Monitoring
Implantable Loop Recorders
Implantable Loop Recorders

Implantable Loop Records (ILR and Linq)

An implantable loop recorder (ILR) is a small device is that is placed under the skin and provides continuous ECG monitoring. It has the capability of monitoring the heart for between two to three years. It is incredibly useful inf patients who suffer fainting spells or infrequent palpitations as other Holter monitoring, does not provide sufficiently long monitoring to capture the necessary the underlying heart problem. 

They also have additional use in those patients with sudden strokes. Some strokes are caused by irregular arrhythmias such as Atrial Fibrillation or Atrial Flutter. If these arrhythmia are found, specific blood thinning medication is required and it is worth while looking for these, particularly if there is a stroke in a younger patient. 

The ILR device itself, sometimes called a Linq (made by a specific manufacturer) is very small and is similar to a USB memory stick. It is impanted under the skin on the front of the chest. This is typically done in a Hospital environment but there are some exceptions where it can be performed in a clinic room if suitable sterile conditions are available.  The best place for the ILR will vary between patients but it is typically just left of the sternum, on the mid-part of the chest. A small cut will need to made and the device is pushed into the flesh. Some minor dissolvable stitches and glue is used to seal the cut.  Patients typically go home the same day. The potential risks of the procedure are bruising and bleeding but this can be minimised. Rarely, in patients who lose a lot of body mass while the device is in place, it can move.  The device is usually removed, under local anaesthetic, once a diagnosis is made. 


AliveCor Monitoring

In some patients, their palpitation episodes are widely spaced out and implantable loop recorder devices are less favourable. An alternative monitoring device is an AliveCor Kardia device. This is a small, medical grade piece of equipment, which pairs with your smartphone.  Whenever you have symptoms, you can place your fingers on the silver pads of the device and the smartphone app will make a recording of the electrocardiogram (ECG). Although this is sold commericially (and is available from Amazon), the recording is of medical grade, and can help make a diagnosis. The AliveCor device will sell you a subscription to remote analysis and cloud storage, but this is not needed. Each recording can be saved as a PDF file and emailed through to Dr Nijjer who can then advise you on the diagnosis. 

The AliveCor equipment is useful when we are monitoring chronic arrhythmia and we may ask patients to purchase these devices to help guide treatment decisions. In other cases, when symptoms are repeatedly not captured on Holter monitoring, an AliveCor can clinch the diagnosis. 


AliveCor Kardia
AliveCor Kardia
Apple Watch ECG monitoring
Apple Watch ECG monitoring

Apple Watch

The Apple Watch, Series 4 and above, has ECG monitoring capabilities.  Prior versions of the Apple Watch can monitor heart rate, but does this through infra-red technology which has some limits. The Series 4 can measure an ECG by making a ‘lead’ between the back of the watch and a finger on the opposite hand. The finger will press on the designated button and the Apple Watch will measure the electrical current through your body to compute an ECG.  This is not the same as a 12-lead ECG, but it is sufficient to perform heart rhythm analysis. This means we have detected important arrhythmias such as Atrial Fibrillation on Apple Watches.  In general, there is insufficient research data to say these devices are safe enough to provide routine monitoring, but they have certainly alerted patients to potential problems through their intelligent algorithms.  

A word of caution: having an Apple Watch, or other similar device, can lead to significant anxiety as patients can often be distracted by multiple warnings and alerts about heart rate, even when there is no medical problem. It is worth talking to Dr Nijjer specifically about this. 


Real life Patient Stories of Holter Monitoring

I kept having palpitations and had seen my GP several times but nothing had been found. I had even worn a Holter monitor but it had not recorded anything. Dr Nijjer recommended a Zio monitor which I wore for 14 days. Although it did irrate my skin a little, it found the problem and I am now getting the right treatment!
Recurrent palpitations can be troubling
A Real Patient Story
My palpitations were really scraring me. They would come out of the blue and it felt like I was going to die. Thanks to Dr Nijjer he found the diagnosis quickly and really reassured me. I thought I would need a lot of medicines but he helped me with mindfulness exercise and a reduction in coffee which really surprised me. Thank you!
A Real Patient Story
I have a serious arrhythmia which was not seen on several A&E stays. I felt terrible and I knew there was real problem. Dr Nijjer organised tests and showed that I had a serious problem that needed ablation. He organised this for me and I feel a lot better. I still need to take medications and blood thinners which cause some bruising but I am very grateful.
A Real Patient Story

Other Cardiac Tests


An electrocardiogram can detect arrhythmia or evidence of prior heart attack. Patients having palpitations may need monitoring over 24-72 hours. Some may need 14-day monitors.


An ultrasound of the heart will show us if there is any weakness or damage. Heart valves may be leaking and need monitoring over time

Cardiac Blood Tests

Cardiac troponin and B-type naturetic peptide provide very sensitive assessment of your heart muscle function

Exercise Testing

Exercise testing can help assess the electrocardiogram (ECG) during acute physical stress. This can be useful for some palpitations that occur during exertion.

Contact us for more information

Would you like to Discuss more? Please call us:

0203 9838 001

We understand how frightening it can be when you are worried about your heart. Our team will act quickly to get you an appointment and any tests required. Often we can do tests on the same day. Call now and see how we can help you.

Contact Us

Please send us your details and we will contact you. Dr Nijjer will strive to help you. 

Dr Sukhjinder Nijjer Consultant Cardiologist

One Heart Clinic
68 Harley Street
London, W1G 7HE

0203 9838 001

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