Implantable cardioverter defibrillator (ICD)
An implantable cardioverter defibrillator is a device that constantly monitors your heart’s electrical activity. It can “automatically” detect severe racing of the heart rate and
treat it.
The implantable cardioverter defibrillator is used to stop serious cardiac arrhythmias (accelerations) (tachycardia or ventricular fibrillation). Indeed, if they are not stopped quickly can progress to a permanent cardiac arrest.
Implantable cardioverter defibrillator
The aim of an implantable cardioverter-defibrillator is to stop severe cardiac arrhythmias (accelerations).
These are essentially severe ventricular arrhythmias (tachycardia or ventricular fibrillation) that can progress to permanent cardiac arrest if not stopped quickly.
In many studies, the implantation of these prostheses has shown a very significant reduction in overall and rhythm-related mortality in selected patients.
This completely autonomous prosthesis is placed under the skin near the collarbone and is connected to the heart by one or more leads. This device continuously monitors the patient’s heart rhythm and is able to recognise potentially serious arrhythmias, which it will then try to stop.
The defibrillator then has two options for stopping these episodes of tachycardia:
- it can either deliver a rapid ventricular stimulation, which has the advantage of being almost painless for the patient but with the risk of being ineffective;
- or (in case the first method fails) the defibrillator can deliver an electric shock, which may be unpleasant for the patient but has the advantage of almost always stopping the initial arrhythmia.
Note that in most defibrillators, a pacemaker is incorporated, which aims to avoid any risk of the heart slowing down.
Who do we offer an implantable cardioverter defibrillator?
There are two types of indication for patients eligible for a defibrillator:
- Firstly, the indications for secondary prevention, i.e. in patients who have already had severe arrhythmias that they have survived and for whom medication does not offer sufficient security against recurrence.
- Secondly, the indications for primary prevention in patients who have never had an arrhythmia but who have a heart condition at high risk of developing these rhythm disorders.
It is your cardiologist, often in consultation with specialist teams, who will be able to suggest implantation of this equipment according to your medical history and your precise cardiological condition.
How is the installation of a defibrillator?
The implantation of a defibrillator requires hospitalisation, generally from two to four days and will take place following a consultation with an anaesthetist.
The procedure itself is very similar to that for implanting a pacemaker and lasts between 30 and 60 minutes: it is carried out under sedation and local anaesthetic with an incision of 4 to 5 cm below the right or left collarbone.
Using a vein found under the skin and a radiology system, one or more leads will be guided in and fixed to the inside of the heart, then connected to the defibrillation device, which will be slid under the skin where the incision has been made.
The recovery is generally short and straightforward, and the risk of severe complications is less than 1%. It is usually expected that you will be able to return home two days after the procedure.
What happens after installation?
Temporary precautions are however necessary; in particular, any significant movement of the shoulder on the side of the operation should be avoided for one month after the procedure.
Certain permanent precautions exist but are rare. It is possible to use a mobile phone, but it should be kept at a distance of 10 cm from the defibrillator. A safe distance of 50 cm away from induction hobs in kitchens is desirable. Finally, avoid going through security gates at airports.
You will be given a defibrillator card or book after the implantation and this can be presented to the customs authorities in order to avoid going through these gates.
The only slight restriction for those with defibrillators in terms of medical examinations is MRI scans. It is now possible, but requires the device to be checked and adjusted before and after the scan.
Those with defibrillators may drive a car, and it only represents a potential limitation for professional drivers.
How is the monitoring of an implantable cardioverter defibrillator?
Monitoring your defibrillator will require one to two annual visits to your heart rhythm specialist in addition to your usual cardiological monitoring. The purpose of this is to check that the device is functioning properly and will let you know if you have had any abnormal accelerations of the heart, since everything is recorded in the device’s memory.
Patients are now usually offered remote cardiological monitoring. Patients can even be given a box to be connected up at home, which allows daily automatic communication between the defibrillator and the box, which sends information to your clinic to allow even more effective monitoring of your equipment.
The lifespan of a defibrillator is generally six to eight years, and the box will need to be changed after this period. There are five manufacters of defibrillator implanted in France: Abbott, Biotronik, Boston Scientific, Medtronic and Microport.