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Arrhythmia services

Diagnosing and treating disturbances in heart rhythm

What are arrhythmias?

Arrhythmias are disturbances in cardiac (heart) rhythm and are very common.

There are many different types of arrhythmia, including simple extra beats and more sustained rapid beats. Disturbances of rhythm can also sometimes cause slow heart beats. 

The symptoms experienced are varied. Some people may notice simple ‘skips and jumps’, others rapid heart beats. Sometimes dizziness or less commonly blackouts may occur.

About us

We run specialist arrhythmia clinics at both Guy's and St Thomas'. We also provide regular pacemaker and defibrillator clinics to support the arrhythmia clinics.

All our clinics are run by a consultants known as electrophysiologists, who treat patients with arrhythmias. 

Find out how imaging is transforming care for cardiac patients

At Guy's and St Thomas’ cardiologists are working to improve the way they use imaging to diagnose and treat patients with cardiac disorders, such as arrythmia.

  • How imaging is transforming care for cardiac patients – video transcript

    Prof Mark O’Neill: One of the challenges facing us today is applying a new paradigm to the management of our patients with cardiovascular disease. With our diagnostic capabilities we can personalise our investigation of a patient and subsequently personalise the treatment of that patient.

    Prof Reza Razavi: By not only looking at the patient's history and their ECGs but actually by looking at the substrate at what's going on inside the heart we can have a some idea of which patients are likely to respond and which might not.

    Prof Aldo Rinaldi: We can use data that's been derived from magnetic resonance imaging or even CT scanning imaging now and this can give us an idea of the patient's anatomy by using computer modelling we can test whether a patient will respond to therapy so we're moving much more towards the sort of precision or targeted approach in individual patients try to improve response. 

    Prof Mark O’Neill: Guy's and St Thomas' is one of the largest teaching hospitals, university hospitals, in the United Kingdom based in the centre of London there has in fact been a St Thomas' Hospital based on the Southbank of the Thames since the 12th century. The clinical and intellectual atmosphere here is unique together with my colleagues in bioengineering and advanced cardiovascular imaging including MR physics we have the ability to answer very quickly questions which we ask. All under one roof. We're seeking to expand the boundaries of how diagnostic imaging can inform therapeutic intervention in patients with heart rhythm disturbances, to understand why a particular patient on a particular day suffers a rhythm disturbance which could potentially be fatal. In the United Kingdom at least 1.5 to 2 percent of our population suffers with atrial fibrillation therefore it's very important for us to find better ways to manage this condition in a more cost-effective way. The current interventions we use seek to ablate or destroy in a controlled way clearly defined cardiac tissue. Advanced cardiac imaging allows us to assess atrial structure. It's important for us to understand which parts of the atrium are the sites that we should target and also how safely can we target them. Sitting here within the XMR environment, we have the ability to take a patient on the morning of their procedure, perform a scan to assess their atrial structure and function, and then to tailor our procedure according to that individual patient's anatomy and depending on where we see sites with scar or abnormal tissue or sites with thick or thin atrial tissue.

    Prof Aldo Rinaldi: Cardiac resynchronisation therapy is an extremely powerful treatment. But approximately a third of patients don't respond to this treatment. By looking for areas of scar, by looking for areas of late electrical or mechanical activation and by using that data and taking it into the catheter lab to actually guide the procedure at the time, we hope to be able to then make a bespoke treatment for the patient to guide the lead to the optimal position in that patient's heart to improve the response to therapy. We were also able to develop in conjunction with our biomedical engineers here, biophysical models derived from MRI and electrical input. We can actually test in silicone what the response to a patient's treatment will be before we actually give it to the patient. There are several studies and programmes we're undertaking in conjunction with other centres in the UK and Europe actually to validate these models. Also we want to make the models more sophisticated and require less invasive data. We want them to be quicker as well so we hope to be able to now create this in hours to minutes in the future.

    Prof Reza Razavi: When we are looking at patients with ventricular tachycardia, cardiac MR allows us to image the shape and size of the ventricle in its function but particularly it allows us to image the scar and the areas around the scar, the border zone, or the grey zone, but getting that information into the cardiac catheterisation laboratory is difficult. That is why we're pursuing doing these procedures inside the MR scanner where we can both observe the substrate accurately but also accurately to target it by tracking our device to do the ablation, the catheter into the right part of the substrate. We can ablate arrhythmias in patients inside an MR scanner for atrial flutter but doing this for ventricular tachycardia is much harder. We have developed the technologies working with Siemens Healthcare and Imricor to be able to do this in an animal model and a next step over the coming year or two for us is to translate that into studies in patients.

    Prof Mark O’Neill: Almost every patient we see is interested in understanding better why they have suffered the problem they have suffered. Therefore every patient who comes into hospital contact with a doctor or a nurse is offered the opportunity, if appropriate, to participate in a research study.

    Dr Ronak Rajani: The UK's National Health Service indicates that all patients should have access to clinical research should they wish to be involved in research. We do screening of patients as they attend their clinics and patients are identified if they have specific pathological conditions or clinical disease states and if these conditions match up to current research studies they are approached for inclusion into these research studies. The transition of clinical data acquisition will ultimately be dependent on the publication and dissemination of our research findings but we are already starting to see that patients are benefitting from some of the work that's being conducted on our site.

    Prof Mark O’Neill: With the support of the infrastructure provided by the NHS, King's College London and our in-house services in bioengineering medical physics, cardiovascular imaging and interventional cardiac electrophysiology we hope that our work using imaging technology to assess arrhythmia substrate in patients will lead to earlier identification of patients for whom intervention is appropriate and better interventions in those patients.


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Email: gst-tr.cardiology 

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