An ICD (Implantable Cardioverter Defibrillator) is a type of cardiac device that is used in patients with potentially dangerous heart rhythms or at risk of these.
The device sits over or under the msucle on the left side of the chest and is attached to one or two leads which are passed down via a vein at the top of your chest into the heart. One lead goes into the bottom chamber of the heart (the ventricle) and, if needed, one lead sits in the top chamber of heart (the atrium). The device monitors your heart continuously forpotentially dangerous heart rhythms. If it detects one of these rhythms, the device can deliver a small electric shock which can restore the heart to its normal rhythm.
There are two types of ICD:
Your Cardiologist will discuss the risks and benefits of the two types and together, decide which type of device is right for you.
There are certain heart conditions that mean your heart is more likely to develop a dangerous fast heart rhythm. These include certain types of heart failure (when the heart doesn’t pump as effectively as it should) and certain types of heart muscle disease (cardiomyopathies).
These dangerous heart rhythms usually originate from the bottom chambers of the heart (the ventricles) and are known as ventricular fibrillation (VF) or ventricular tachycardia (VT). If your heart goes into one of these rhythms, the heart is pumping too quickly to fill properly and cannot pump blood effectively around the body. You may feel palpitations, light-headed or develop chest pain. You may even lose consciousness and it may be fatal. Having an ICD if this happens could be life-saving!
This depends on which type of ICD you are having. The procedure is usually straightforward and is often performed as a day-case. The procedure is performed either with local anaesthetic and sedation (medicine which makes you sleepy) or with a general anaesthetic.
A small incision is made in the skin in the upper chest and a pocket is made under the skin for the generator or battery. One or two leads are passed through a vein in the chest which runs down into the heart. The leads are positioned in the heart and one end is then attached to a generator which is placed on top or below the muscle in the chest. The wound is closed with sutures (stitches).
If you are having a subcutaneous ICD (S-ICD) this is implanted under a general anaesthetic (i.e. you will be asleep). Before hand, you will have an assessment to ensure that this type of device is suitable for you. Unlike a transvenous ICD, the lead from an S-ICD is not inside the heart, but simply under the skin in your chest . The lead is then connected to a generator, which is buried on top of the muscle in the side of your chest. The wound is closed with sutures.
Depending on which type of sutures your Cardiologist uses, you may need to have your sutures removed in 7-10 days. The hospital staff will advise you if and when you need to have your sutures removed. You will also be given a card explaining what device you have and when and where it was put in. It is important you carry this card with you at all times.
The main risks from the procedure depend on the type of device you are having fitted are They include infection, bleeding and bruising, scratching the surface of the lung (pneumothorax), bleeding around the heart and the risk of the leads moving. Almost all the complications can be treated at the same time.
The wound should take a couple of weeks to heal. It is important that, at least for the first week, you keep the wound clean and dry to minimise the chances of the wound getting infected. It is also important that, if you have a transvenous ICD, you don’t lift your left (or right if the device is right sided) arm above your shoulder for at least 6 weeks. This is because the lead takes this long to “bed in” and become fixed. If you lift your arm too soon, you could dislodge the ICD lead from position. This could mean that the device can’t monitor your heart rhythm or can’t deliver a shock effectively. If this happens, you may need another procedure to reposition the lead.
After you have your ICD put in, you will have it checked after 1 month. This is to ensure that the device is working effectively and that there aren’t any problems. After that, it is usually checked every 6 months – 1 year. Your local Cardiology department will give you a contact number for the device department. If you think you’ve had a shock from your ICD or if there are any problems with your device, you should get in contact with them. They can then check the device and see if the device has given you a shock and if it’s working the way it should.
You will not be able to drive for a period of time after the procedure and will need to inform the DVLA. The time you are restricted from driving depends on the reasons why the device was implanted.
The ICD battery (or generator) will last for around 7-10 years. After this time, it will need replacing. This is a straightforward procedure. The leads can stay in as long as they’re working effectively. The majority of leads never need replacing and last the rest of your life.