Implantable Cardioverter Defibrillators (ICDs)
What is an ICD?
An ICD consists of a pulse generator and between one and three leads that are threaded underneath the collarbone (usually the left collarbone) into the heart. Each lead is typically a thin lead and about the thickness of a piece of spaghetti. The defibrillator itself is in many ways similar to a pacemaker but is often a little larger and is typically the size of a matchbox. It works by monitoring the heart rhythm continuously and has all the features of a pacemaker but has the additional ability of being able to give the heart a shock if there is a dangerous heart rhythm.
The ICD itself has an inbuilt battery which will typically last between 6 and 10 years and like most electrical items it’s battery life depends on how much it is being used from a point of view of being a pacemaker and how many times it needs to deliver shock therapy. The leads themselves are secured into the heart muscle by very fine small screws at the ends and then they are attached to the ICD system. The entire system is stored under the skin so there is nothing visible aside from the surgical incision from which the ICD has been implanted. The incision is typically 5-6cm across.
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Professional
Trusted
Take a look at Davids profile on iWantGreatCare and see what others have said about his work.
Experienced
David is one of the UK’s most active doctors in the field, performing an impressive volume of procedures each year.
Still have some questions?
If you still have some unanswered questions or a general query about this specific condition please get in contact and we can give you anymore information you require.
FAQ's
ICDs are implanted for one of two reasons. Firstly some ICDs are classed as “primary prevention” – these are ICDs that are implanted into patients that the cardiologist feels are at particular risk of having a dangerous heart rhythm problem that can be fatal.
These heart rhythms that concern cardiologists are either ventricular tachycardia (VT) or ventricular fibrillation (VF). Patients that are commonly implanted with “primary prevention” ICD devices are often patents that have had heart attacks in the past and have been left with weakness to the heart muscle and often a scar.
Other patients who we offer primary prevention ICDs can have a muscular disorder of the heart such as hypertrophic cardiomyopathy (HCM) or arrhythmogenic right ventricular dysplasia (ARVD). There are other rarer conditions also that exist for which we offer “primary prevention” ICDs including Brugada syndrome and Long QT Syndrome.
These are ICDs that are implanted in patients who have survived a “sudden cardiac arrest”. This is a problem where a patient has already had a dangerously fast heart rhythm such as ventricular tachycardia or ventricular fibrillation and has had to be admitted urgently to hospital and has survived the event. As they are at high risk of a recurrent event we will often discuss and offer them an ICD in case it happens again.
The ICD is typically implanted under local anaesthetic and conscious sedation (see website). We very rarely fully anaesthetise patients. ICD implantation is not the same as open heart surgery. They are most commonly implanted under the left collarbone and typically takes 45-90 minutes to implant. The wound is closed with stitches with surgical glue onto the surface of the skin and therefore no stitches are required to be moved as the stitches that we use are dissolvable.
Typically patients will be in hospital for 24 hours and will have an overnight stay. After the device has been implanted we usually perform a chest X-ray to ensure that there are no problems with the leads or the lungs. The ICD is checked electronically prior to discharge and then patients are seen 2-4 weeks later for a further check to ensure it is working appropriately. With modern ICDs patients are given a home monitoring service which allows the ICD to wirelessly talk to the monitor and upload data to our central database so we can check the progress and monitor the operation of the ICD. This will be monitored at the hospital in which you had the ICD implanted. It is called “remote monitoring”.
‘Chest X-Ray appearance of a patient with a Biventricular ICD (three leads) in situ’
Most household and hobby items do not interfere with the ICD. Mobile telephones can be used but we generally recommend that they are used in the opposing ear that the ICD is implanted (if under the left collarbone use the phone next to your right ear), satellite navigation modules, induction hobs and microwave ovens are all safe to use with an ICD in situ.
Standard battery charges, electric shavers, electric blankets and hairdryers are not known to interfere with ICDs. If you do have an induction hob it can be used but we generally recommend you stay 60cm away from the induction surface.
If you have any specific questions about something unusual that you may have then the manufacturer of the implant itself (Medtronic, Boston Scientific, Abbott, Biotronik) will have an exhaustive list on their website which will allow you to get further information.
If you have a shock that comes without warning and you have had no symptoms you should call the hospital in which you have had the ICD implanted as soon as possible. You will have information from the hospital implant centre with contact numbers to allow you to do this.
If you have a remote monitor you can arrange an upload of what your heart was doing at the time of the shock. If you had a shock at the time of feeling unwell (ie; you were symptomatic) or have any worries at all you should call an ambulance so that you can be taken into hospital and be examined.
If you have more than one shock in close succession this is regarded as a medical emergency and you should call an urgent ambulance.