Why are you being offered the implantation of an automatic defibrillator?

You are offered the installation of an implantable cardioverter defibrillator (ICD) because you are in one of the following two situations:

- You have a heart condition that puts you at risk of sudden death in connection with the occurrence of serious heart rhythm disorders in the coming months or years. These serious heart rhythm disorders are caused by untimely increases in heart rate and can sometimes be fatal if not treated in time.

- You have just had a serious heart rhythm disorder. The risk of recurrence is high despite the treatments that could be proposed and can lead to sudden death.

International scientific studies have shown that, in these cases, the implantation of an ICD increases the probability of survival compared to an identical population that did not benefit from the implantation of an ICD.

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At the same time, in the case of heart failure and according to certain criteria, it may be useful to implant an ICD with an additional function called "resynchronization". Resynchronization reduces the signs of heart failure in about 70% of implanted patients.

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How does an automatic defibrillator work?

An ICD has a box, powered by a battery. It is able to continuously analyze the heart rhythm, detect abnormal rhythms and treat them either by rapid, unfelt stimulation or by an internal electric shock. In addition, this device has the function of a pacemaker (maintaining the heart rate in the event of an excessive slowing down of this rate) and highly developed "memory" functions. This system, set up during a surgical procedure at the level of the upper part of the chest (or exceptionally at the level of the abdomen), is connected to the heart by one, two or three probes inserted through the vein.

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How does the implantation work?

- It is necessary to fast, with pre-operative preparation carried out (antiseptic shower in particular). An allergy to an antibiotic or injectable iodine products should be reported prior to the procedure. This will take place on an operating table in a specially equipped room and can be done either under general anesthesia or local anesthesia.

- In the case of local anesthesia, the doctor performs a puncture to make the local anesthesia, to make the incision and then the compartment for the box.

- The lead(s) are placed through one or more vein(s) addressed in the area where the box is implanted. The lead(s) are then positioned in the heart chambers under radiological control.

- During the operation, it is sometimes necessary to trigger cardiac arrhythmias and deliver shocks via the ICD in order to check that the device is working properly.

- The operation lasts an average of one hour, sometimes more depending on the type of equipment implanted and the difficulties of setting up the probes, in particular the probe for resynchronization.

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For the particular case of the subcutaneous defibrillator, the box is implanted in a left lateral chest compartment and the single probe is placed in the subcutaneous tissue, generally on the left edge of the sternum thanks to one or two small additional incisions.

 

In some cases, you may also be offered the placement of a subcutaneous defibrillator connected to a subcutaneous probe. In this case, there is no material inside the heart or vessels.

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What are the risks associated with the implantation of the defibrillator?

Like any surgical procedure, the implantation of a defibrillator exposes to an anesthetic risk as well as possible complications, particularly infectious or hemorrhagic, in about 5% of cases. Very rarely, these complications can be fatal.

At a distance from the implantation of a defibrillator, a reoperation may be required to compensate for a failure of the box, a displacement, a rupture of the leads or an infectious problem. Constant stimulation of the left ventricle as part of resynchronization can also cause a feeling of muscle contraction or hiccups. In addition, the case will be replaced after a few years of operation (5 to 10 years depending on the model), due to battery wear.

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Finally, it is important to understand that ICD technology is very complex and exposes to a risk of malfunction that may require specific care ranging from more frequent follow-ups to reoperation and sometimes even the change of equipment.

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How is the follow-up after hospitalization performed?

After the operation, regular follow-up in a specialized center is necessary (approximately every 3 to 6 months) to check that the device is working properly, as well as that there are no complications. This "technical" monitoring in the specialized center does not replace but complements the regular monitoring by your treating cardiologist. In some cases, additional follow-up can be carried out remotely (without coming to a consultation) using a specific device (this is called telecardiology).

A card indicating that you have a defibrillator will be given to you at the end of your operation. The mark of the ICD, the date of implantation and the contact details of the implanting centre will be collected.

 

Your daily life will most often be little changed by wearing this device.

​However, certain precautions must be taken when performing medical or surgical procedures, and sometimes at the professional level. They will be explained to you in a way adapted to your personal situation by the implanting doctor and his team. There are patient associations that can also listen to you.