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Pacemakers and defibrillators
A pacemaker is a small, lightweight device which is implanted to treat problems caused by an abnormally slow pulse. The device consists of a pulse generator which houses the battery and electronics and the pacing leads which allow the pulse generator to sense the patient's heart beat as well as stimulate (pace) the heart to beat. A defibrillator is a slightly larger device which has all the functions of a pacemaker with an important additional ability to detect fast, dangerous and life threatening heart rhythm disturbances and in that event deliver a life-saving shock to restore normal rhythm. Defibrillators are therefore offered to patients who are particularly vulnerable to such life threatening rhythm disturbances.
The procedure of device implantation
Pacemakers are usually implanted under a local anaesthetic in a specialised procedure room called a cardiac catheter lab. The device is implanted just under the collarbone (usually on the left side) via a small (4 cm) incision. Guided by X-ray visualisation one, two or three pacing leads (depending on type pacemaker) are passed into a vein near the collarbone and positioned within the heart . The leads are then thoroughly tested to confirm stable positioning and good function. The pacing leads are then connected to the pulse generator which is implanted in a comfortable position just under the skin. The incision is then sutured with absorbable stitches. The procedure typically last 60-90 minutes and patients are usually discharged from hospital the following day.
Ongoing care after implantation
The pacemaker will begin to function immediately after implantation. It is normal to experience some soreness around the wound and some swelling and bruising can be expected. Simple oral pain relief tablets such as paracetamol or ibuprofen should be effective treatment. Although rigorous arm movements should be avoided for the first fourteen days after implantation, natural use of the arm and shoulder is encouraged. Precautionary antibiotics are prescribed for five days after implantation during which time the wound should be kept clean and dry.
The pacemaker is checked 6 weeks after implantation, then 6 months later and annually thereafter. At each appointment the patient's symptoms and progress are assessed together with the data from the pacemaker which is downloaded from the device wirelessly with specialised equipment. This allows us to programme the pacemaker settings to match an individual patient's needs.
The battery life of the pacemaker is dependent on how much pacing is required and will differ between individual patients. Typically, the battery (pulse generator) needs to be replaced every 7-10 years. The procedure to replace the pulse generator is generally shorter than the original implantation as the pacing leads do not normally need to be replaced.
Biventricular pacemakers differ from conventional pacemakers by have an additional pacing lead to pace the main pumping chamber of the heart (the left ventricle). They are suitable for specific patients with heart failure who also have cardiac electrical conduction abnormalities as seen on their ECG (electrocardiogram).The implantation procedure is very similar to conventional pacemaker implantation but may take longer due the additional pacing lead (typically 90-120 minutes).
Implantable Cardioverter-Defibrillators (ICDs)
ICDs are prescribed to patients who are vulnerable to fast, life-threatening arrhythmias (specifically, ventricular tachycardia or fibrillation). Such patients may be those who have survived a cardiac arrest or who may have a genetic predisposition to life-threatening arrhythmias (eg.Brugada and Long QT syndrome) or even patients with severely enlarged and weakened hearts.
The technique for implanting ICDs is almost identical to that for pacemakers. However, because part of testing ICD function at implantation involves checking the ability to deliver an appropriate "shock" it is often more comfortable for the patients to have a general anaesthetic for ICD implantation.
Driving restrictions for patients with pacemakers and defibrillators
Patients with pacemakers are restricted from driving for one week after implantation for group 1 licence vehicles (motor cars and motor cycles) and for six week after implantation for group 2 licence vehicles (lorries and buses). Implantation of an ICD results in a lifelong bar from group 2 licence entitlement. The DVLA regulations for recipients of an ICD holding a group 1 licence vary depending on the indications for implantation and are available from the DVLA website: Regulations are often reviewed and updated and we would encourage the reader to refer to the DVLA website for up-to-date guidelines.