Permanent Pacemakers and Implantable Defibrillators (ICDs)

Permanent pacemakers are usually implanted for patients whose heart beats too slowly at times.  Implantable defibrillators (ICDs) are similar but slightly larger devices which are usually implanted for patients who have already had a problem with certain types of dangerously fast heart rhythms, or are considered at high risk of such a rhythm.  Wires are positioned in the heart via a vein and connected to the device or ‘generator’ which is implanted under the skin of the upper part of the chest, most commonly on the left side.  Pacemakers are usually implanted under local anaesthetic, whilst defibrillators may be implanted under either local or general anaesthetic. The device is then checked every so often using wireless technology.  Patients with a pacemaker will be asked to visit the hospital from time to time, whilst ICD patients will often be offered a special unit to take home which can send information to the hospital about the device’s function without the need to visit.

What are the benefits?

A pacemaker should prevent the patient from feeling unwell or collapsing due to the heart going too slowly.  A defibrillator will not necessarily prevent a dangerously fast rhythm, but will return the rhythm to normal by either pacing the heart very quickly or by shocking the heart internally.

Are there any alternatives?

If the heart doesn’t go very slowly and the patient does not experience any symptoms then it may be appropriate to simply keep an eye on the patient.  Certain drugs can be used to reduce the risk or frequency of dangerously fast rhythms, but in the highest risk patients the evidence suggests that drugs alone are not enough and the patient may still be at risk.

What are the risks?

There is a small amount of risk associated with implanting a pacemaker or ICD.  There is around a 1-2% risk of creating a temporary air leak around the lung (called a pneumothorax) which is treated by draining the air, developing a blood collection around the device which requires draining, or developing an infection related to the device.  A very small number of patients will develop a problem with their device which may mean needing to check it more often or, very rarely, even change the device.

Consultants linked to treatment

Location where service is offered

Royal Brompton Hospital and Harefield Hospital

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Case Studies

Patient Video: Pacemaker fitting for arrhythmia

John shares his story about having treatment at Harefield Hospital, under the care of Consultant, Dr David Jones.
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