Defibrillator implant

What is an implantable cardioverter-defibrillator (ICD) / defibrillator?

A defibrillator, also called an ICD, is an implantable system comprising of two highly sophisticated parts: lead and a generator (control centre and the battery unit). The device detects, analyses, stimulates and if needed, shocks the heart back to normal rhythm. All standard defibrillators also have a pacemaker function to stop the heart from going too slow. There are special defibrillators such as subcutaneous defibrillators that does not have the pacemaker function. The defibrillator component is always on standby ready to act if sustained dangerous abnormal rhythm is detected. It is designed to stop dangerous abnormal heart rhythms (Ventricular tachycardia; VT and ventricular fibrillation; VF) with a special manoeuvre called anti tachycardia pacing (ATP) or deliver a shock from the inside to reset the rhythm.

The defibrillator wire is usually placed within the heart through veins located just under your collarbone / clavicle. It is usually on left side but can be implanted from the right side as well. The wire(s) are then connected to the generator / battery unit and placed in a space over the chest muscle under the skin. The generator / battery unit is large and does sit prominently in the chest under the collar bone.

Do I need a defibrillator?

The primary purpose of the defibrillator is to protect you from dangerous abnormal rhythms such as sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) that can result in sudden death. In some people, the defibrillator is recommended to prevent sudden death, (Primary prevention). Once you have had sustained VT or VF and survived the event, you are generally recommended to have a defibrillator to prevent another event (secondary prevention).

What are symptoms of ventricular tachycardia (VT) / ventricular fibrillation (VF)? 

With VT or VF, you can experience unexpected dizziness, collapse, loss of consciousness and chest pain. People can die suddenly and unexpectedly from VT or VF.

 Do defibrillators prevent abnormal rhythms?

No, it is important to understand that defibrillators will not prevent abnormal rhythms. They are like having in insurance policy. You hope you never need to use it. Medications are used to prevent abnormal rhythms.

The device will detect fast abnormal rhythm and will deliver therapy to regulate your heart rhythm. You may or may not feel your usual symptoms before you receive therapy from the device. The device acts very quickly but many people may develop symptoms such as loss of consciousness, dizziness or palpitations before the device had delivered therapy.

 What can defibrillators do?

Defibrillators are highly sophisticated. They have pacemaker function in addition to the defibrillation capacity. If the heart rhythm is too slow, it can pace your heart to a minimum predetermined rate. This can be adjusted in clinic if required. If the heart is going too fast due to VT, it can deliver quicker stimuli that is aimed at interrupting the rhythm which may restore normal rhythm – “Anti-Tachycardia Pacing”. The device can deliver a high energy shock between the shock coil in the heart and the generator that resets the heart rhythm – “defibrillation” / “shock”.

What is a defibrillation or shock?

A shock has been described by people as a sudden “kick in the chest” which can be painful and distressing. Some people have described it as “startling”, “jolting” and “unsettling”. The feeling is momentary. In very rare cases, people can have repeated shocks in which case, you must attend the local emergency department without delay. Call for help and do not drive. Any person touching you should not be harmed.

Are there different types of defibrillators?

Yes, there a different type of defibrillators. In general defibrillators can have 1, 2 or 3 wires. Most common Is the two-wire system called a dual chamber defibrillator. Instead of using the veins to place these special wires within the heart, in highly selected cases, the wires can be placed outside the heart. This system is called a subcutaneous ICD.

Different companies manufacture these devices with their own unique offerings. Common defibrillator brands are Medtronic, St Jude Medical, Boston Scientific, Biotronik, Sorin to name a few.

What are the risks of having a defibrillator?

 They include but are not limited to the following.

Common risks and complications (more than 5%) include:

• Bruising / bleeding at the device site
• Large collection of blood (Haematoma) – this can take several weeks to settle
• Pain at the device site

Uncommon risks and complications (1- 5%) include:

• The device lead(s) can move. The lead will need to be put back into place by repeating this procedure
• Bad bruising if you are taking blood thinning drugs such as Warfarin, Xarelto, Eliquis, Dabigatran Aspirin, Clopidogrel (Plavix or Iscover) or Dipyridamole (Persantin or Asasantin)
• Unexpected device failure. There is a risk of battery (generator) or lead failure. This is uncommon but means the battery or lead will need to be removed and a new one put in
• Infection of the device site. This will need treatment with antibiotics and/or removal of the device and leads
• Inappropriate shock from the device (some studies have quoted this as >10%)

Rare risks and complications (less than 1%) include:

• A punctured lung (pneumothorax). This may require a tube to be inserted into the chest to reinflate the lung
• Blood clot in the subclavian vein (Deep vein thrombosis)
• A hole is accidentally made in the heart or heart (perforation) – This will need surgery to repair
• Blood clot in the lung (pulmonary embolus)
• Heart attack
• A stroke. This can cause long term disability
• Death is possible due to the procedure or other heart problems
• Tricuspid regurgitation
• Infection of heart valve and other infections

What are the costs associated with a defibrillator implant?

If you are having this procedure in a public hospital as a public patient, the cost is covered by Medicare.  If you are having this procedure in a private hospital, there is no additional out of pocket cost for our specialists. The usual hospital excess applies. Some anaesthetists have an out-of-pocket cost that we encourage you to discuss prior to your planned procedure.

How do I prepare for a defibrillator implant procedure?

You will receive a letter with instructions and steps required prior to your procedure including, date of admission, fasting instructions, medications to stop and items to bring with you. You will usually need recent blood test for your kidneys and blood count prior.

In General, do not eat or drink for 6 hours before your procedure. Ask your doctor about taking your usual medications. Blood thinners maybe discontinued for 24hrs. If you take SGLT2 (dapagliflozin / empagliflozin) medicine for heart failure or diabetes, you will need to stop taking them at least 3 days before your surgery. Leave any personal items of value such as jewellery at home.

What happens when you arrive at the hospital?

Once you arrive at the hospital for your procedure, you will usually be directed to the cardiac catheter laboratory / operating theatre admission area where you will be formally admitted as a hospital patient. You will be asked to change into hospital gown and put away all your valuable belongings. You will have some basic tests such as ECG, have your vitals recorded, upper chest shaved and have a cannula inserted into your arm to assist with the procedure.

What happens during the procedure?

Defibrillator insertion is a very common procedure and takes approximately 1 hour. Procedure is usually performed in the catheter laboratory or operating theatre. You will be lying on a narrow bed under the X-ray machine arm that can move in and out of position. The procedure is usually performed under sedation. Medication to make you sleepy will be given through the cannula to keep you relaxed during the procedure. General anaesthesia may be considered in some cases and may require an arterial line to monitor your blood pressure. Antibiotics are usually given prior to the procedure.

Once you are comfortable, the upper chest is usually shaved again if needed, cleaned with a special antiseptic wash and once dry, a long sterile drape is placed over the site. The drape covers you from head to toe. You will have someone to assist you if needed. Local anaesthetic is administered at the incision site which numbs the area. You’ll feel an initial sharp and burning or pricking sensation when the local anaesthetic is injected but it quickly becomes numb in less than a minute. You may feel a pulling / pushing sensation during the operation which is normal.

A 6 to 9cm cut is made just below your collarbone. The tissue under the skin is carefully dissected and a space is created just above the chest muscle. Usually, a needle is advanced into the vein deeper in the chest under the clavicle. Special dye (Contrast) injection maybe required to identify the vein. The special lead is guided into the vein and advanced into the correct chamber of your heart using X-ray scan. They are secured to the heart chambers tissue by a tiny screw at the end of the wire (Active lead). The leads are secured to the underlying muscle with permanent sutures over a special cuff on the wire called suture sleeve.

The other end of the wire is connected to the defibrillator battery unit, which is placed in the pocket created over the muscle. The wound is closed with absorbable sutures and a water-resistant dressing applied on top of the wound.

In selected cases, we may have to test the function of the defibrillator by delivering a shock through the device at the time of the procedure which will require you to be more sedated / asleep. We may have to induce the dangerous abnormal rhythm to test and ensure that the device if able to respond appropriately. This is not usually required.

You’ll usually need to stay in hospital overnight and may have a chest Xray that night. A device check is performed the next morning. People can usually go home the next day if tests are all normal.

What happens after a defibrillator implant?

At the end of your procedure, a simple dressing is applied over the device site. You may have a larger dressing applying pressure at the site overnight. You’ll be watched closely in a recovery area, and depending on how you feel, you might need to rest in bed for a while. You will be admitted to the ward for observation overnight with rhythm monitoring. A chest X-ray may be performed in some cases. People are usually discharged the next day after a device check.

What happens after discharge?

Wound Care:

1. The dressing on your wound should be left in place for two weeks. You may shower, as it            is waterproof, but you cannot submerge yourself in a bath or pool.
2. Two weeks after the operation, please go to your GP to have the dressing removed. Do not remove or change the dressing before this time.
3. If the wound becomes red, hot, swollen, more painful or starts to drain fluid, see your local doctor immediately, or call my rooms on 9500-0266.

Special Issues:

1. DRIVING: You may drive after two weeks. You cannot hold a commercial driving licence once you have a defibrillator. Every time the device treats an abnormal rhythm either with ATP or a shock there is a driving restriction following the event that can range between a week and 6 months. You can find out more about the driving restrictions from the Austroads website {link to website: https://austroads.com.au/drivers-and-vehicles/assessing-fitness-to-drive}
2. MOVEMENT OF SHOULDER: Please minimise the use of the shoulder on the side of the operation for one month.  Do not raise your arm to above shoulder height, do not use the     arm to push out of a chair, and no heavy lifting for one month.  This is to ensure that the       flexible wires connecting the defibrillator to your heart do not move.  After a month these    will be firmly stuck in position by the body’s healing process.
3. It is normal to take Paracetamol (Panadol) for the first few days at home.

Other Special Issues:

As outlined in the information booklet that you have received from the device company, these relate to things such as mobile phone use, use of machinery and certain medical tests or procedures you may need in the future, some of which may either interfere with the defibrillator, or need the defibrillator to be adjusted beforehand.

The device / generator can sometimes move down slightly over time. If it is not too much and the wires are not pulled back, this is of no concern.

Airline Travel:

You will be given a card with the details of your defibrillator on it, please keep this in your wallet.  A permanent card (resembling a credit card) will be sent to you in about two months.  Show this to the security check at the airport, they will search you with a wand rather than walking through the usual metal detector gate.

Follow Up:

You will be sent an appointment to see me in 2-3 months to have the defibrillator checked.  Usual follow up thereafter is 6-12 monthly appointments to keep track of the device function. It is recommended that you continue your usual follow up with other treating specialists and medical practitioners involved in your care as usual. If you do not receive an appointment, please call my rooms on 9500-0296.

IF YOU RECEIVE A SHOCK FROM YOUR DEFIBRILLATOR:

If you are feeling fine, call my rooms the next day.  If you have more than one shock, or are feeling unwell afterwards, please go the Emergency Department.

By law, you are not permitted to drive a vehicle for one month after receiving a shock from the device.

Do I have to take it easy once I have a defibrillator?

Most people with a defibrillator lead normal active lives, including your normal sexual activities. You can participate in your physical activity after two – four weeks. Many devices allow for increased heart rate when exercising. There may be some restrictions on competitive sports due to your underlying condition rather than the defibrillator.

What can’t I Do?

Defibrillators work by detecting electrical signals within your heart. There are external sources of electromagnetic signals that interfere with your device and safest to avoid. The device cannot differentiate between electrical signals from your heart and outside your body. Some examples of activities or situations to avoid include: some types of welding, poorly grounded electrical appliances, and industrial equipment with a large magnetic field. Avoid carrying your mobile phone in your shirt pocket on the same side as your device. In general, people with defibrillators can no longer hold a commercial licence. You will not be allowed to drive a truck, bus or taxi.

How long do defibrillators last?

The wires can last for decades but as with most things there is wear and tear over time. The battery lasts about 10 years depending on a few factors. The battery unit is replaced at that time (generator change).

Can I have an MRI scan after a defibrillator?

Yes, MRI scans can usually be performed with newer models. There are some exceptions to this rule including abandoned leads and special scenarios. You will have to wait for at least 6 weeks before an MRI scan. Check with your doctor about the details.

Can I use a cell phone or microwave oven if I have a defibrillator?

Microwave ovens, electric blankets, remote controls for TV and other common household appliances won’t affect your defibrillator. You can use a cell phone, if you take these steps:

• Hold the phone to the ear on the side of your body opposite from your device.
• When your phone is on, try to keep it at least six inches away from your device. For example, don’t carry your phone in your breast pocket over your device.

Remote monitoring:

We can monitor the function of your defibrillator while you are at home via remote monitoring. This can be through the transceiver that you place near your bed or through your smart phone. All important information is stored within your device and the remote monitor communicates with your device wirelessly overnight at a prespecified time. It will do so every night and transmit information 1-6 monthly to a team of technologists who analyse that information. If there is an urgent issue, information will be transmitted that night and the doctor will usually be informed the next day.

Generally, almost all people will be offered remote monitoring to keep track of your device while you are at home. There is a free service and a paid service (External 3^rd party – Remote Rhythm Management). Please feel free to discuss this with your doctor.

Please contact the rooms if you have any questions or concerns at any time.

In recommending this procedure your doctor has balanced the benefits and risks of the procedure against the benefits and risks of not proceeding. Your doctor believes there is a net benefit to you going ahead. This is a very complicated assessment.