When not to implant As well as knowing who might benefit from ICD therapy, it is important for treating physicians to know who is not an appropriate candidate see Table 3. This includes patients with VT or VF within the first 48 hours of an acute MI due to electrolyte abnormalities or due to the effects of drug use or intoxication.
Patients with incessant VT or VF are also not candidates for an ICD until their arrhythmia is brought under control with antiarrhythmic or ablation therapies. Similarly, patients whose life expectancy is less than 1 year due to cardiac or noncardiac disease are not likely to survive to benefit from an ICD.
Competing interests Dr Tung has received research funding from Medtronic Canada. He has also received speaking fees from Boston Scientific Canada and St. Jude Medical Canada.
Closed-chest cardiac massage. JAMA ; PubMed abstract 2. Lee TH, Goldman L. The coronary care unit turns Historical trends and future directions. Ann Intern Med ; PubMed abstract 3. The coronary care unit. New perspectives and directions. PubMed abstract 4. Kastor JA. Michel Mirowski and the automatic implantable defibrillator. Am J Cardiol ; contd. PubMed abstract 5. Precursors of sudden coronary death. Factors related to the incidence of sudden death. Circulation ; - PubMed abstract 6.
Gillum RF. Sudden coronary death in the United States: — Circulation ; PubMed abstract 7. Mendeloff AI. Pacing Clin Electrophysiol ;14 5 Pt 2 PubMed abstract 8. Mower MM. PubMed abstract 9. Am J Cardiol ; PubMed abstract Standby automatic defibrillator. An approach to prevention of sudden coronary death. Arch Intern Med ; Termination of malignant ventricular arrhythmias with an implanted automatic defibrillator in human beings.
N Engl J Med ; Use of implantable cardioverter defibrillators in Canadian and US survivors of out-of-hospital cardiac arrest. CMAJ ; Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest: The Cardiac Arrest Study Hamburg CASH. A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias.
Canadian implantable defibrillator study CIDS : A randomized trial of the implantable cardioverter defibrillator against amiodarone. Cost-effectiveness of the implantable cardioverter-defibrillator versus antiarrhythmic drugs in survivors of serious ventricular tachyarrhythmias: Results of the Antiarrhythmics Versus Implantable Defibrillators AVID economic analysis substudy.
S-ICDs are only used for patients who do not also require a pacemaker for slow heart rhythms. Traditional implantable cardioverter-defibrillators ICD sit in the chest and send a shock to the heart when they sense an abnormal rhythm. Inova cardiac surgeons place the device below the skin and connect it to the heart with electrodes. This device is designed to deliver two levels of electrical energy.
A low energy shock can convert a beating heart that is in an abnormal rhythm back to a normal heartbeat. A high energy shock is delivered if the arrhythmia is so severe that the heart is only quivering instead of beating.
At that time, it was indicated only for patients who had a documented cardiac arrest or life-threatening arrhythmia. The implantation of these devices was difficult and required electrodes to be placed directly on the surface of the heart. The device itself had to be placed in the wall of the upper abdomen as it was too large to be placed in the chest.
By the early 's, the devices no longer required wiring directly on the heart, but allowed for wiring that went through the vein to the inside surface of the heart. This made the implant procedure much easier and the recovery much quicker just overnight. Tell your doctor if you are sensitive to or are allergic to any medicines, iodine, latex, tape, or anesthetic agents local and general.
You will need to fast for a certain period before the procedure. Your doctor will tell you how long to fast, usually overnight. Tell your doctor of all medicines prescription and over-the-counter and herbal or other supplements that you are taking.
Tell your doctor if you have heart valve disease, as you may need to take an antibiotic before the procedure. Tell your doctor if you have a history of bleeding disorders or if you are taking any blood-thinning medicines anticoagulants , aspirin, or other medicine that affect blood clotting. You may be told to stop some of these medicines before the procedure. Your doctor may request a blood test before the procedure to see how long it takes your blood to clot.
Other blood tests and chest X-ray may be done as well. Having an ICD implanted may be done on an outpatient basis or as part of your stay in a hospital. You will be asked to remove any jewelry or other objects that may interfere with the procedure. An intravenous IV line will be started in your hand or arm for injection of medicine and fluids, if needed. You will be connected to an electrocardiogram ECG monitor that records the electrical activity of the heart during the procedure using.
Your vital signs heart rate, blood pressure, breathing rate, and oxygenation level will be monitored during the procedure. You will receive a sedative in your IV before the procedure to help you relax. However, you will likely remain awake during the procedure. Once the anesthetic has taken effect, the doctor will make a small incision at the insertion site. A sheath, or introducer, is inserted into a blood vessel, usually under the collarbone.
The sheath is a plastic tube through which the ICD lead wire will be inserted into the blood vessel and advanced into the heart. It will be very important for you to remain still during the procedure so that the catheter does not move out of place and to prevent damage to the insertion site. The lead wire will be inserted through the introducer into the blood vessel.
The doctor will advance the lead wire through the blood vessel into the heart. Once the lead wire is inside the heart, it will be tested to verify proper location and that it works. There may be 1, 2, or 3 lead wires inserted, depending on the type of device your doctor has chosen for your condition. Fluoroscopy, a special type of X-ray that will be displayed on a TV monitor , will be used to position the lead. For subcutaneous ICDs, one or two small incisions are made near the top and bottom of the sternum or breast bone.
The lead wire is then tunneled underneath the skin next to the sternum and from the sternum to the incision on the left side of the chest.
The ICD generator will be slipped under the skin through the incision just below the collarbone for traditional ICDs and on the left side of the chest for S-ICDs after the lead wire is attached to the generator.
Generally, if you are right-handed, the device will be placed in your upper left chest. S-ICDs are implanted on the left side of the chest near the heart. If you are left-handed, or have a contraindication to a left-sided device a traditional ICD can be placed in your upper right chest. Certain tests may then be done to assess the device function. After the procedure, you may be taken to the recovery room for observation or returned to your hospital room.
A nurse will monitor your vital signs. Tell your nurse right away if you feel any chest pain or tightness, or any other pain at the incision site. After the period of bed rest has been completed, you may get out of bed with help. The nurse will help you the first time you get up, and will check your blood pressure while you are lying in bed, sitting, and standing. Move slowly when getting up from the bed to avoid any dizziness from the period of bed rest.
You will be able to eat or drink once you are completely awake. Your arm may be in a sling for a day or so. How long you will need to wear a sling will depend on your provider. Some people are asked to wear it at night while they sleep after the first couple of days but can take it off during the day. After the procedure, a chest X-ray is often done to check the lung and make sure the systems are stable.
Your doctor will visit with you in your room while you are recovering. The doctor will give you specific instructions and answer any questions you may have. Once your blood pressure, pulse, and breathing are stable and you are alert, you will be taken to your hospital room. If the procedure is done on an outpatient basis, you may be able to leave after you have completed the recovery process. However, it is common to spend at least 1 night in the hospital after ICD implantation for observation.
You should be able to return to your daily routine within a few days. Your doctor will tell you if you need to take more time in returning to your normal activities.
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