Defibrillator Implant


Sarah Lewis, PharmD

What is a defibrillator implant?

A defibrillator implant is the surgical placement of an electrical device called an implantable cardioverter defibrillator (ICD) in your chest or belly. An ICD treats life-threatening abnormal heartbeats (arrhythmias). Arrhythmias can prevent your heart from pumping a sufficient amount of blood to your brain and body. A defibrillator implant uses electrical shocks to restore a normal heartbeat.

Your heart is a muscle that works like a pump. It has four chambers, two upper chambers (atria) and two lower chambers (ventricles). Like all pumps, your heart requires a source of energy to function. Your heart's pumping energy comes from a built-in electrical conduction system.

Your heart's four chambers must pump in harmony with one another to make a normal heartbeat. Electrical signals travel through the chambers to produce the heartbeat. Any malfunction in these signals can make your heart beat too quickly, too slowly, or at an uneven rate. This causes an arrhythmia.

A defibrillator implant is only one method used to treat abnormal heartbeats. Discuss all of your treatment options with your doctor or healthcare provider to understand which options are right for you. 

Types of defibrillator implants

An ICD has two main parts. The first part is the wires with electrodes that connect your heart to the ICD. These wires continually monitor your heart rhythm. They send the information to the second part of an ICD, the pulse generator. 

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The pulse generator is a small battery-operated computer. It is designed to recognize abnormal heart rhythms and respond by sending electrical impulses back to your heart. The pulse generator can send either low-energy pulses or high-energy shocks to correct your heart rhythm. 

The types of defibrillator implants include:

  • Dual chamber ICD. A dual chamber ICD has wires that connect to both an upper chamber and a lower chamber of your heart. It corrects abnormal electrical signals between the two chambers.

  • Single chamber ICD. A single chamber ICD has wires that connect to one or both of your ventricles (the lower chambers). It corrects abnormal electrical signals within the ventricles.

Other procedures that may be performed

In some cases, an ICD is placed during open-heart surgery for other heart problems. These surgeries include:

  • Congenital defect repair corrects a variety of heart problems that are present at birth.

  • Coronary artery bypass grafting (CABG), commonly called heart bypass surgery. A CABG bypasses or provides a new route around diseased coronary arteries with healthy vessels taken from other places in the body. This is the most common heart surgery in adults.

  • Heart valve repair or replacement. Diseased or damaged heart valves do not allow blood to flow properly through the heart and out to the body.

  • Left ventricular assist device (LVAD) implant. The LVAD is implanted in the abdomen and attached to the heart to help a weak heart pump more effectively. An LVAD treats severe heart failure.

Why is a defibrillator implant performed? 

Your doctor may recommend an implantable cardioverter defibrillator (ICD) to treat a life-threatening heart arrhythmia. Arrhythmias of your heart’s ventricles are particularly serious. This includes ventricular tachycardia and ventricular fibrillation. 

Ventricular tachycardia occurs when your ventricles beat too fast. This decreases the amount of blood that your heart pumps to your brain and body. Dizziness and fainting can occur with ventricular tachycardia. It can be life threatening without rapid treatment. 

Ventricular fibrillation occurs when your ventricles beat so fast and unevenly that they quiver, or shake. Little or no blood is pumped to your brain and body. Death results within five to 10 minutes without treatment.

Your doctor may only consider a defibrillator implant for you if other treatment options with less risk have failed to prevent life-threatening heart arrhythmias. Ask your doctor about all of your treatment options and consider getting a second opinion before deciding on a defibrillator implant. 

Your doctor may recommend a defibrillator implant if you have a high risk of a life-threatening heart arrhythmia. This includes people who have had: 

  • A heart attack and are at high risk for sudden cardiac death

  • Episodes of any serious heart arrhythmia, such as a rapid atrial fibrillation. This is a rapid quivering of the upper chambers of the heart.

  • Hypertrophic cardiomyopathy, a complex heart disease characterized by thickened heart muscle and ventricular stiffness

  • Sudden cardiac arrest and survived

  • Ventricular tachycardia. A single episode of ventricular tachycardia can warrant an implantable defibrillator.

Your doctor may also recommend a defibrillator implant for warning signs seen on heart tests. These heart tests include electrocardiography (ECG), ultrasounds, stress tests, and a catheter electrophysiology study.

Who performs a defibrillator implant?

A cardiac surgeon performs a defibrillator implant. Cardiac surgeons specialize in the surgical treatment of conditions of the heart and its blood vessels. Cardiac surgeons may also be known as cardiothoracic surgeons.

How is a defibrillator implant performed?

Your defibrillator implant will be performed in a hospital. The procedure takes a few hours and generally includes these steps:

  1. You will dress in a patient gown and lie on a procedure table.

  2. Your team will insert an intravenous (IV) line to provide fluids and medications.

  3. You will have medication (a sedative) to relax you. You may fall asleep.

  4. A team member will prepare an area of your chest or abdomen (belly). This includes shaving if needed, cleaning, and covering with a surgical drape. This is the area where your surgeon will place your defibrillator.

  5. Your surgeon will numb the area with an injection of local anesthetic. You will not feel anything in the area where your surgeon places the defibrillator.

  6. Your surgeon will thread the wires of your defibrillator through a vein to your heart using real-time X-ray guidance.

  7. Once the wires are in place, your surgeon will make a cut in either your chest or your abdomen and place the pulse generator.

  8. Your surgeon will test the pulse generator once everything is connected. Your team will give you more medication to put you in a deeper sleep when the pulse generator is tested. You will not feel the any electrical pulses during the test.

  9. After the surgeon has tested the defibrillator, the skin will be closed with stitches, tape or glue.

Will I feel pain?

Your comfort and relaxation is important to you and your care team. You may feel a pinch or prick when the IV is inserted and stinging when the local anesthetic is injected. Your doctor will give you sufficient sedative medications so that you are comfortable. Tell your doctor if you are uncomfortable in any way.

What are the risks and potential complications of a defibrillator implant?  

As with all surgeries, a defibrillator implant involves risks and possible complications. Complications may become serious and life threatening in some cases. Complications can develop during surgery or recovery.  

General risks of surgery 

The general risks of surgery include: 

  • Adverse reaction or problems related to sedation or medications, such as an allergic reaction and problems with breathing

  • Bleeding, which can lead to shock

  • Blood clot, in particular a deep vein thrombosis that develops in the leg or pelvis

  • Infection 

Potential complications of a defibrillator implant

Complications of a defibrillator implant include:

  • Blood clots or air bubbles in the vein

  • Collapsed lung

  • Defibrillator malfunction requiring your doctor to reprogram it or replace it

  • Heart or nerve damage

  • Punctured heart or lung

  • Tearing an artery or vein

  • Unnecessary electrical pulses (impulses). This occurs when the defibrillator sends pulses that are not needed. This can damage your heart, cause irregular heart rhythms and pain, and be emotionally upsetting. It is the most common complication of a defibrillator implant.

Reducing your risk of complications

You can reduce the risk of certain complications by following your treatment plan and:

  • Avoiding close or prolonged exposure to electrical devices or devices that have a strong magnetic field. Your doctor will give you specific instructions about these devices.

  • Following activity, dietary and lifestyle restrictions and recommendations before surgery and during and after recovery

  • Notifying your doctor immediately of any concerns, such as bleeding, fever, increase in