Defibrillator Implant

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 is a treatment for life-threatening abnormal heartbeats (arrhythmias). Arrhythmias occur when your heart’s electrical signal causes it to pump too slowly, too fast, or irregularly. 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 in order to function. Your heart's pumping energy comes from a built-in electrical conduction system.

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

ICD placement is a minor surgery. However, it has significant risks and potential complications. You may have less invasive treatment options available depending on your specific circumstances. You should consider getting a second opinion about all your treatment choices before having a defibrillator implant.

Types of defibrillator implants

An ICD has two main parts. The first part is the wires with electrodes that connect to your heart. These wires continually monitor your heart rhythm. They send the information to the second part of an ICD, the pulse generator. 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, a defibrillator implant may be placed during open heart surgery for other heart problems. These surgeries include:

• Congenital defect repair can correct 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 your 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 is used in patients with congestive heart failure.

Why is a defibrillator implant performed?

Your doctor may recommend an implantable defibrillator 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 can pump out to your brain and body. Dizziness and fainting can occur with ventricular tachycardia. It is 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 can result within five to 10 minutes without treatment.