Implantable Cardioverter Defibrillator (ICD) - Procedure & Uses

Sometimes, the heartbeat may get too fast, and the heart muscles get weak, resulting in a condition known as Arrhythmia. This disrupts the natural rhythm of the heart. ICD is used when:

1. The heartbeat is dangerously fast
2. Heart muscles are weak
3. The heart is not able to perform its primary function, i.e., pump blood to all parts of the body
4. Restore heartbeat if the heart abruptly stops beating

An implanted ICD monitors the heartbeat continuously. When it detects an irregularity, the device provides an electric shock to the heart and restores its normal rhythm. 

An ICD is a palm-sized battery-powered device installed in a patient's chest who have:

1. A high risk of getting a ventricular tachycardia, fibrillation, or a sudden cardiac arrest
2. Ventricular tachycardia (rapid heartbeat originating from the heart’s lower chambers)
3. Ventricular fibrillation (a rapid, irregular, chaotic heartbeat)
4. A previous cardiac arrest
5. Ejection fractions (EF) less than 35 per cent (EF is the percentage of blood that a heart pumps with each beat or contraction. A normal EF is about 55 per cent or higher.)
6. A high risk of sudden cardiac death (SCD) due to an inherited abnormality of the heart

An ICD contains a Lithium battery that can last up to five to seven years. When the battery runs out of power, the doctor will recommend replacing the generator with a new one during a minor outpatient procedure. Depending on a patient’s specific conditions, a doctor may prescribe the following types of ICDs for treating Arrhythmia:

1. Single-chamber ICD with a lead attached to the heart’s right ventricle
2. Dual-Chamber ICD which can send signals to the right atrium and right ventricle
3. Biventricular device to send signals to the right atrium and both the ventricles

How Does an ICD Work?

The ICD identifies abnormal heart rhythms and determines the appropriate therapy to restore normal heart rhythm. The ICD is programmed to include either or all of the following functions:

1. Defibrillator: When the heart beats dangerously fast, ICD delivers a high-energy shock to the heart muscle, restoring a normal rhythm. 
2. Cardioversion: The ICD delivers a low-energy shock simultaneously with the heartbeat to restore the normal heart rhythm. 
3. Anti-tachycardia pacing (ATP): In case of Tachycardia i.e when the heart beats too fast, the ICD delivers a series of small electrical impulses to the heart muscle, restoring a normal heart rhythm. 
4. Bradycardia Pacing: When your heart beats too slow, the ICD sends small electrical impulses to stimulate the heart muscle, maintaining a normal heart rate. 

How is the defibrillator implanted?

The selection of an ICD depends on a patient's condition and the opinion of their surgeon. The patient is advised to stay in the hospital overnight and can go home the next day after the procedure. The procedure of defibrillator implantation follows these steps:

1. The patient is made to lie on their back and is made comfortable on the operation table.
2. The surgeon prepares the ICD surgical site by removing any hair and cleaning it with an antiseptic soap.
3. Local anaesthesia is given at the surgical site by injection.
4. An incision is made at the surgical site. A sheath is inserted into the blood vessel and further advanced into the patient’s heart.
5. The surgeon then inserts a lead wire through the sheath into the heart. Sometimes, there is more than one lead wire.
6. After inserting the lead wire, the surgeon tests the location of the lead wire(s) and fixes it through a special X-Ray known as Fluoroscopy.
7. Depending on the case, a patient is given a traditional ICD or a subcutaneous ICD. If subcutaneous ICD is given, the surgeon incisions at the top and bottom of the breast bone. 
8. After making the incisions, the lead wire is channelled next to the breast bone. It is passed from the breast bone to the incision on the left side of the chest.
9. For traditional ICDs, the ICD generator is slipped under the skin below the collarbone. For subcutaneous ICDs, the generator is slipped on the left side of the chest near the patient’s heart. 
10. ICD is generally placed on the opposite side of the patient's preferential use of hand, i.e. if the patient is right-handed, the device is placed in their left chest and vice-versa.
11. The device is assessed for its proper functioning, and during this time, the surgeon may put the patient to sleep for a while.
12. After ensuring that the device is working properly, the surgeon closes the incisions and applies a sterile bandage or dressing.

Before the Surgery

1. A consultation session will be held with the doctor.
2. The doctor will examine the patient’s heart condition with the help of some tests and vitals.
3. A suggestion of suitable implantation will follow this. 
4. The patient is suggested to openly tell the doctor about any medicines or supplements he/she is already taking.
5. The doctor will ask to stop taking certain medications like aspirin to prepare for the procedure. 

What to expect on the day of surgery?

1. The healthcare team will ask the patient to restrain from eating or drinking anything after midnight or on the day of the operation. 
2. He/she will be advised to empty his/her bladder before the operation.
3. The nursing team will inform the patient to remove any jewellery for a smooth procedure.
4. He/she has to wear a gown given by the hospital.
5. The nurse will start an intravenous line (IV) in the patient's arm to inject medicines or fluids.
6. The patient's blood pressure, heart rate, and breathing rate are taken.

What to expect during the surgery?

1. The team will move the patient to a cardiac catheterization or electrophysiology laboratory. 
2. The surgeon will connect an ECG monitor to the patient. It will record the electrical activity of the heart during the treatment.
3. All the vitals are continuously monitored during the surgery.
4. Large electrode pads are placed on the front and back of the patient's chest.
5. The patient is given a sedative through the IV so that he/she can relax during the operation.
6. The patient is asked to remain still during the procedure to prevent any damage to the insertion site.

Recovery at Hospital

1. The ICD procedure can take around one to three hours to complete.
2. The patient is shifted to the recovery room after the procedure and advised to take rest.
3. Vitals, like heart rate, blood pressure, pulse etc are checked while lying down, sitting, and standing.
4. The patient will be advised to get up slowly from the bed. 
5. The patient's condition is monitored, and if all is well, he/she will be asked to go home. 
6. The patient will need someone to drive him/her home. 

Recovery at Home

1. The doctor restricts some daily activities of the patient depending upon his/her condition. 
2. The patient is advised not to lift his/her affected arm over the head for two weeks.
3. Recovery will take place within four to six weeks.
4. The patient should avoid lifting heavy weights after the procedure for at least one month.
5. It is also advised not to drive for a few months after the implantation procedure.
6. The patient can return to normal activities in a few days, depending on the doctor's advice.
7. The patient should take proper care to keep the insertion site clean and dry.

Life After ICD

The patient must take some precautions after the implantation of an ICD, which include:

1. They should wear a card or an identification stating the type of ICD they have for security and first aid care.
2. Care has to be taken while talking on a cell phone. A patient is advised to keep the cell phone more than six inches away from the ICD site. 
3. They cannot undergo some procedures such as magnetic resonance angiography (MRA), magnetic resonance imaging (MRI), and radiofrequency or microwave ablation. 
4. The patient should stand at least 2 feet away from high-voltage transformers, motor-generator systems, or welding machines. 
5. They should keep magnets, headphones, and wireless chargers at least 6 inches away from the ICD site, as these can interfere with the working of an ICD. 
6. The patient should avoid driving with an ICD as it can pose a threat to themselves and others. 

First Follow up Appointment 

1. The first follow up can be done as per the doctor's advice. It usually takes place after two to four weeks. During the first follow up, the doctor will check if the device is working effectively or not and ensure that there are no problems with the device.  The device will be checked again after every six months or one year. 
2. When the ICD delivers a shock for the first time, the patient should try to remain calm by taking deep breaths. If required, go to the emergency room. The doctor will tell them how to deal with it.
3. It is advised that the patient talks to the doctor openly about their feelings and how the procedure has affected their health. 

The common side effects which may occur after the procedure include:

1. Fever
2. Infection at the implant site
3. Swelling, bruising or bleeding from the incision

The possible complications after an ICD implantation include:

1. Damage to the blood vessels from the ICD leads
2. Bleeding around the heart 
3. Regurgitation (blood leakage from the heart valve)
4. Pneumothorax (collapsed lung)
5. Dislodge of the leads 

The sequelae of not treating the complications of ICD in time include:

1. Bleeding around the heart can be life-threatening
2. Dislodge of the leads may cause cardiac perforation

Call your healthcare professional if you experience any side effects or complications mentioned above. 

Suppose a patient is suffering from any of the above symptoms or conditions. In that case, their heart may not be able to pump blood efficiently to the body. The doctor must treat this disturbed heart rhythm immediately by installing a defibrillator. If the treatment is delayed, it can be dangerous, leading to:

1. Symptoms like shortness of breath, light-headedness, & chest pain, which may aggravate further.
2. Fatality occurs if the heart stops pumping blood.