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Cardiothoracic Services

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ICD Nurse Specialists

An implantable cardioverter defibrillator (ICD) looks similar to a Pacemaker and is a little bigger than a matchbox. It is usually implanted under the collar bone.


An ICD is programmed to the best settings for your condition. The ICD can give the following treatments and your cardiac physiologist or ICD Nurse Specialist will explain the particular settings relating to any individual patient.

Anti-bradycardia pacing pulses

If the heart beats too slowly, the ICD can send small impulses to the heart, generating extra heartbeats when required. These are called paced beats. As these impulses are very small they are not painful and normally go unnoticed. The heart may beat slowly for a few seconds following treatment for a fast heart rhythm. The device can tell when pacing is needed and will provide this for as long as necessary.

Anti-tachycardia pacing (ATP) pulses

If the heart beats too quickly, the ICD can send out faster pacing impulses which can help the heart get back to a normal rhythm.

This can be done within a second or two and most people are not aware this has happened. However it is not uncommon to experience palpitations or feel light-headed or dizzy.

ICD shocks

If the heart rate is very fast, or if the anti-tachycardia pacing has not corrected the rhythm, the ICD can deliver a shock. The energy of these shocks is between 31 and 41 Joules and can often feel like a hard blow or kick to the chest. Most people describe these shocks as painful if they occur when they are conscious, and this can occasionally cause psychological problems. However most shocks occur when a patient is unconscious as a result of the arrhythmia, and occasionally the shocks go unnoticed, particularly if they occur during sleep. Any shock that has happened will be recorded on the device and the cardiac physiologist or ICD nurse specialist will identify this during follow up checks.

ICDs are used for people who have had a previous life-threatening abnormal heart rhythm and are at risk of another one. They may also be used for people who have not had a life-threatening abnormal heart rhythm before, but tests have shown that they are at risk of one in the future. However, there are many people who have had an episode of a life-threatening heart rhythm, during or just after a heart attack, who would not necessarily need to have an ICD.

ICDs are inserted under local anaesthetic, but with sedation, so the patient will feel very sleepy. Patients usually stay overnight in hospital and the ICD is then checked thoroughly before they leave.

ICD Nurse Specialists

The ICD Nurse Specialists are based at the John Radcliffe Hospital and provide pre-implant education and information, pre-assessment, follow-up care and support for ICD patients within Oxfordshire and its referring areas.

There is close collaboration with the Consultant Electro-physiologists, Cardiac Physiologists and Arrhythmia Nurse Specialists. Patients are seen pre-implant then followed up at least every six months in the outpatient setting or via remote monitoring.

We currently treat around 600 patients, with approximately 100 new implants each year. Devices are now also routinely used to treat certain patients with heart failure. Patients are encouraged to return to as full and active a life as possible, using cognitive behavioural therapy techniques as required.

Services include:

  • pre-implant education and support
  • nurse-led follow-up clinic for device interrogation, medication review, symptom review and psychological support
  • remote monitoring
  • access to 24 hour telephone helpline and email
  • emergency access in the event of ICD shocks
  • patient and family education days.

Find us and contact us

ICD Nurse Specialists
Outpatients Blue Area
Level 2, John Radcliffe Hospital
Oxford OX3 9DU

Tel: 01865 221667

From the main John Radcliffe Hospital entrance, follow the corridor down just past the main lift area. The clinic is located on the right hand side in the Outpatients Blue Area.

How to find the John Radcliffe Hospital