Preparing for your. ICD or CRT device

Transcription

1 Preparing for your ICD or CRT device

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3 Contents What is an ICD?... 1 What heart rhythms does an ICD treat?... 3 What is a CRT device?... 4 Who is suitable for an ICD?... 5 How is the ICD implanted?... 6 What happens after my ICD is implanted?... 7 This booklet was prepared by Paul Nolan, Chief Cardiac Technician UHG. This Croí publication was supported by an unrestricted educational grant from sanofi-aventis.

4 What is an ICD? ICD stands for Implantable Cardioverter Defibrillator. This a small electronic device placed inside the chest to prevent sudden cardiac arrest due to dangerously fast heart rhythms. These devices are implanted under the skin (like a pacemaker). They constantly monitor the heart s rhythm and can deliver treatments for dangerously fast heart rhythms. They (like a pacemaker) will also treat any slow heart rhythms. An ICD consists of two main parts: A Pulse generator This small box contains the battery and circuitry (brains) of the ICD. Modern pulse generators will fit into the palm of your hand. Leads Depending on your device, you will receive one or two leads. These are specially designed thin, flexible wires which connect the pulse generator to the chambers of your heart. 1

5 Aorta SA Node Left Atrium Right Atrium Left Ventricle Right Ventricle 2

6 Preparing for an ICD What heart rhythms does an ICD treat? ICDs treat two rhythms, both of which come from the bottom chambers of the heart. (The bottom chambers of the heart are called the ventricles, the ventricles pump blood around the body.) The first rhythm is Ventricular Tachycardia, commonly known as VT. When the heart goes into this rhythm, the bottom chambers of the heart beat extremely fast. Some people will be symptom free but most will experience some degree of symptoms. These can include a sensation that your heart is racing, dizziness, fainting and/or a blackout. Your device will be set up based on whether you have had this rhythm in the past and the treatment given by the device will depend on your symptoms. The second rhythm is Ventricular Fibrillation or VF. In this case the rhythm in the bottom chambers becomes chaotic and the chambers quiver instead of pump. During VF no blood gets pumped by the heart and the person blacks out very quickly. This is commonly referred to as a Cardiac Arrest. This type of rhythm is fatal unless treated quickly with a special shock delivered across the heart, resetting your heart into its normal rhythm. This is called defibrillation and your ICD will be set up to deliver this shock in the event that you have an episode of VF. 3

7 What is a CRT device? Some patients may receive a Biventricular pacemaker or Cardiac Resynchronisation Therapy device (CRT). This is a type of pacemaker which also contains an ICD. It s function is to restore the normal coordinated pumping action of the ventricles. This also consists of a generator and three leads going into the heart. Most CRT devices function as an ICD, so all the points regarding ICD apply to the CRT. The CRT device paces both the left and right side of the heart in an effort to make the pumping action of the weakened heart more efficient. These devices are only suitable for certain patients and not all patients who receive such a device will find a benefit in terms of symptoms. What does this shock feel like? Because the ICD reacts so quickly to a dangerous heart rhythm, most patients will not blackout but will be aware of the shock. The sensation of the shock varies from patient to patient but most people describe it as getting a swift thump in the chest. Some people will never receive a shock from their device but the important thing to remember is that if you do, then it is highly likely that your ICD has delivered life-saving therapy. 4

8 Preparing for an ICD Who is suitable for an ICD? There are many reasons why patients may need an ICD. A member of our cardiology team will discuss with you why you need an ICD and this will be recorded in the notes section of this booklet. The majority of patients who receive an ICD suffer from a condition called Dilated Cardiomyopathy or Heart Failure. These patients have never had a dangerous heart rhythm but research has taught us that they are at an increased risk of developing dangerous heart rhythms. We implant the device just in case a patient develops this rhythm in the future. This just in case approach is known as a prophylactic implant. Some patients are known to have dangerous heart rhythms. Either they have had a Cardiac Arrest and survived, or are known to have Ventricular Tachycardia which cannot be fully controlled by medications or where symptoms are severe. Other patients have conditions, usually genetic, which means they are at risk of these dangerous heart rhythms. These conditions include Hypertrophic Cardiomyopathy (HCM and HOCM), Long QT Syndromes and Brugada Syndrome. If you have been diagnosed with any of these conditions and require more information please ask a member of the Cardiology team. 5

9 How is the ICD implanted? Most people are admitted to hospital the evening before or on the morning of their procedure. Patients should come in fasting. The procedure itself is a relatively minor one and takes approximately one hour. However, you may wish to let your relatives know that you will be away from the ward for two to four hours. In the majority of cases you will be discharged from hospital the following day. You will be admitted by a member of the cardiology team who will ask you routine questions regarding your medical history. They will carry out a routine physical examination which involves listening to your heart and lungs and taking some blood samples. The procedure is carried out in the Cardiac Catheterisation (Cath) Lab by a specialised team which includes Cardiology doctors, nurses, technicians and radiographers. If you have not been to the Cath Lab before, it may seem like a busy and daunting place but we will do our best to put you at ease. You will be given medication (sedative) to relax you, then a local anaesthetic will be applied to an area in front of the left shoulder. Once this has taken effect a small incision is made which allows the doctor to make a small pocket or pouch which will hold the ICD. After this, a special needle is inserted into a vein near the pouch. The lead is threaded through this small needle into the vein and then into the heart. The ICD is then connected to the lead, you will not feel this happening. Following the insertion, certain tests will be carried out on the device. You will be sedated for these tests and will be unaware of them. 6

10 Preparing for an ICD Are there any risks with this procedure? Implanting an ICD is a relatively low risk procedure. However, there are some potential risks which include infection or damage to a blood vessel or lung. The risks will be fully explained to you by one of the Cardiology doctors on the ward before you sign the Consent Form. This is an ideal time to ask any questions you may have. What happens after my ICD is implanted? After your device is implanted you will stay in a recovery area for a short period of time and then you will return to the ward. In the majority of cases you will be discharged from hospital the following day. Your device will be checked prior to discharge. This is a 15 minute procedure carried out by one of the Cardiac Technicians. It is an ideal opportunity for you to ask any further questions. We will also give you your own ICD information pack to take away. Once you have left hospital, we will continue to carry out routine follow ups on your device every three months. Obviously it will take you a little time to recover once you are home. We will ask you to refrain from certain activities until we see you for your first check-up, eight weeks after the implant. We will give you those instructions prior to you leaving the hospital. However after this eight week check-up, we would expect that you will be back doing all the activities which you were doing before your implant. 7

11 If you have never had a history of a dangerous heart rhythm and have got a prophylactic device then you may return to driving once the stitches are removed. If you have a history of dangerous rhythms, there may be some restriction to driving. This will be discussed with you by your Cardiologist and you should follow his or her recommendation, not only for your safety but also for the safety of your passengers and other road users. If, in the future, you end up receiving an appropriate shock from your device, then your cardiologist may instruct you to refrain from driving for a period. Again, this is not only for your safety but also others. It is important to remember that it is not the device which will prevent you from driving but the heart rhythm. For further information please read our other booklet: Living with your ICD or CRT device or contact the ICD clinic (091) or (091)

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