Purpose:
An ICD may be used in the following cases:

• Ventricular fibrillation (quivering or erratic pumping of blood)

• Ventricular tachycardia (an extremely fast heart rhythm)

• Previous heart attack

• History of heart disease

• Cardiomyopathy (enlarged or thickened heart muscle)

• Heart failure

• Inherited, congenital (present at birth) heart defects like long QT syndrome
  

The symptoms that start to appear which indicate the requirement of an ICD are- 

• Pain in the chest

• Tachycardia and Bradycardia 

• Dizziness and Weakness

• Shortness of breath

• Fainting 

• Sweating

• High blood pressure

• Sleep apnea

1. Electrocardiogram (ECG): An ECG is performed to measure the electrical activity of the heart, and diagnose problems with the heartbeat of the patient.
2. Echocardiogram: This test uses sound waves to create images of the size and structure of the heart, and how blood flows through the heart.
3. Holter monitoring: The Holter monitor is a wearable device that keeps track of the rhythm of the heart and spot irregular heart rhythms that has been missed by an ECG. It is usually worn for one or two days.
4. Event recorder: An event recorder is similar to a Holter monitor and requires the person to push a button when symptoms are felt. It can be worn for a longer time than a Holter monitor.
5. Electrophysiology study: Flexible tubes called catheters are guided through a blood vessel into the heart. It helps in the identification of the area causing an irregular heartbeat.

The procedure can be performed in two different ways:

1. Endocardial or transvenous approach:

• This procedure is performed under local anesthesia (the area of the procedure is numbed).
• The surgeon makes small incisions or cuts in the chest.
• The lead is inserted through the cut into a vein, which is guided to the heart with the help of x-rays.
• One tip of the lead is attached to the heart muscle, and the other end is attached to the pulse generator.
• The generator is placed under the skin of the upper chest.
• The patient usually stays in the hospital for one day after the procedure.

2. Epicardial or surgical approach:

• This is the less common method used for an ICD.
• This procedure is performed under general anesthesia (the patient is put asleep during the procedure).
• The doctor places the generator in a pocket that is created under the skin in the lower abdomen.
• The patient usually stays in the hospital for 3 to 5 days after this procedure.

Once the leads are in place, they are tested by the doctor to make sure that they are working properly and are in the right place.
Small amounts of energy are sent through the leads into the heart, causing the contraction of the heart. This is known as the lead function test or pacing.
After the leads have been tested, the doctor connects them to the ICD device.
The doctor then uses a programmer or external device for making the final device settings.
The procedure may take two to four hours to complete.

Complications of the ICD surgery can include:

• Infection
• Bleeding
• Swelling
• Bruising
• Damage to the blood vessels
• Regurgitation (leakage of blood through the heart valve)
• Pneumothorax (collapse of lungs)
• Movement of the leads or device causing heart perforation

• It is normal to have some pain and tenderness after the procedure.
• The doctor may prescribe a pain killer to relieve the pain and discomfort after the procedure.
• Avoid heavy lifting and strenuous activities for at least one month after the procedure.
• Avoid driving for at least six months after the procedure. Driving can be resumed only if one can go for long periods of time without any shock (approximately 6 to 12 months), or if one does not faint after a shock.
• Follow-up appointments with your doctor every three to six months after the procedure are required. The doctor will program your device.
• The battery in the device lasts for approximately five to seven years. A separate procedure will be required to replace the batteries.
• Certain objects like security systems, medical equipment like MRI machines, and power generators may interfere with the performance of the device, and hence you should avoid them.
• Keep mobile phones and smartwatches at least six inches away from the ICD device.
• Carry an ID with you, stating what type of ICD you have.
• Contact your doctor if you have any problems with the ICD device, or if it delivers a shock for restarting the heart.