What is an Implantable Cardioverter-Defibrillator?
An ICD is an electronic device that is implanted beneath the skin, with electrical leads connecting it to the heart. The device keeps track of the heart rate, monitoring the heart for arrhythmias arising from the lower chambers. If a dangerous arrhythmia is detected, the device delivers an electric shock. This resets the heart, allowing normal sinus rhythm to return. An ICD is often referred to as a “defib” by doctors and patients.
Your doctor may have recommended an ICD implant because you have previously had a ventricular arrhythmia (VT or VF), or because you are at risk of having one due to your heart’s condition. Heart failure, prior heart attack, and other diseases of the heart muscle are common situations where an ICD may be of benefit.
The components of an ICD are in some ways similar to a pacemaker, and one device is sometimes mistaken for the other. A pacemaker is used to treat slow heart rhythms, and it cannot deliver electric shocks to treat dangerously fast heart rhythms like VT or VF. In contrast, the primary function of an ICD is to treat VT or VF, although it can also function as a pacemaker if required.
ICD implantation may be performed during an elective admission, or during an unplanned inpatient stay.
If you are having an elective procedure, you will receive a letter from the hospital bookings clerk or doctor’s secretary outlining the date, time, and other details of your hospital admission for the procedure. A nurse may call you to confirm your personal and medical details. You will need to attend a blood collection service for a blood test within the week prior to your procedure.
You will receive specific instructions about any medications changes that are necessary prior to your procedure. If you are unsure about the instructions, please do contact the clinic for clarification.
You must fast for at least six hours before your procedure. If your procedure is in the morning or early afternoon, do not eat or drink after midnight, except for a sip of water to help you swallow your pills. If your procedure is in the mid to late afternoon, you may have a light, early breakfast.
During your admission, pre-operative checks will be performed before transfer to the operating room. The operating room has a movable patient bed, an X-ray machine, ECG monitors, and other equipment.
ECG electrodes and patches will be attached to your chest and back. These will feel cool on your skin. An anaesthetist will insert a fine intravenous tube usually into the back of your hand before administering a sedative. A second tube may be placed into the artery of your wrist to monitor blood pressure. The entire procedure takes 1 h and is normally performed under local anaesthesia with sedation to make you comfortable.
The ICD is implanted beneath the skin, usually below the left collarbone. The area is cleaned with a sterile solution. You will be given an antibiotic for protection against microbes and a sedative through an intravenous line. A large sterile sheet will cover your body and will partially cover your face.
You will receive a local anaesthetic injection to the area below the collarbone which will sting momentarily. Thereafter, the area will be numb. You may feel some pressure in the area as the doctor is working, and you should feel no pain. If you do, please inform anaesthetist or nurse who will be by your side attending.
One or two leads will be threaded through a vein and positioned in your heart under X-ray guidance. These are then connected to the ICD which is positioned under the skin before the incision is sewn over and dressed.
ICD implantation is a routine procedure. Some bruising can occur and is normal. More serious complications are uncommon, and are dealt with promptly where they arise.
These include the following.
- Infection. Infection at the surgical site is treated with antibiotics. The ICD may need to be removed to clear the infection.
- Haematoma. This is a large blood clot beneath the skin that causes swelling and may take some weeks to settle.
- Pneumothorax. Partial collapse of the lung may due to a small perforation from a needle. This often heals spontaneously although in some cases a small tube to the chest is required to help drain the air leak. This delays discharge by a few days.
- Lead dislodgement. An ICD lead sometimes moves out of place shortly after the procedure, and needs to be repositioned.
- Cardiac perforation. This is a rare complication where one of the ICD leads penetrates the heart wall causing blood to accumulate around the heart. If this occurs, it will be dealt with immediately.
After the procedure, you will return to the recovery ward before being transferred to a normal hospital ward.
It is usual to stay in hospital for 1-2 nights after the procedure. There will be some bruising and discomfort at the implant site which normally settles over the following weeks.
You will need to arrange for a family member or friend to pick you up from the hospital following discharge. A follow-up appointment will be arranged 1 month post procedure or earlier if necessary.
- Wound care. A waterproof dressing is placed over your incision and must remain in place for a week. You may remove it carefully thereafter. Make an appointment to see your GP a week after the procedure to check that the wound is healing well. You may have your GP remove the dressing if you prefer.
- Rest and recovery.For 4 weeks, you must avoid strenuous exercise, heavy lifting, and raising your elbow above your shoulder. This includes golf, bowling, and swimming. You may return to driving after 2 weeks, unless you are disqualified from driving for another reason.
- Contact details. Prior to your first follow-up appointment, it is best to contact the treating team for any post-procedure issues, as they will be most familiar with the details of the procedure. For public patients, contact the Alfred Heart Centre on 03 9076 3263. For private patients, contact the Heart Rhythm Clinic on 03 8560 0535. If the clinic is closed or the treating doctor or nurse not available, please proceed to your GP or local emergency service for evaluation.
Living with a ICD
- Your ICD will need to be checked around 1 month after implant.
- Thereafter, you will need to have it checked every 3 to 6 months.
- When the battery runs low, you will need surgery to replace the ICD.
- Tell your doctors and dentist that you have a ICD. Certain types of medical equipment may affect the way the ICD works.
- Tell airport security that you have a ICD. Ask the guards not to use hand held metal detectors on you.
- Carry an ID to let others know that you have a ICD.
- Stay away from magnets and strong electric fields.
- If you work around industrial microwaves, electricity, or large motors, ask your doctor about possible effects.
Microwaves and Mobile Phones
Microwave ovens, electric blankets, remote controls for TV and other common household appliances won’t affect your ICD.
You can use a cell phone, too, if you take these steps:
- Hold the phone to the ear on the side of your body opposite from your ICD.
- When your phone is on, keep it at around six inches away from your ICD.
- For example, don’t carry your phone in your breast pocket over your ICD.