Implantable Cardioverter Defibrillator (ICD)
What is an Implantable Cardioverter Defibrillator?
An ICD is a battery-powered device placed under the skin that keeps track of your heart rate. Thin wires connect the ICD to your heart. If an abnormal heart rhythm is detected the device will deliver an electric shock to restore a normal heartbeat.
ICDs are useful in preventing sudden death in people who have a high risk of life-threatening arrhythmias.
Some of these severe medical conditions like ventricular tachycardia (VT), or ventricular fibrillation (VF); may lead to patient’s death.
Most dual function ICDs (also called transvenous ICDs) can also serve as pacemakers.
A person is a candidate for an ICD if they have a life-threatening arrhythmia without correctable causes, such as the following:
Acute myocardial infarction (heart attack)
Myocardial ischemia (inadequate blood flow to the heart muscle)
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Electrolyte imbalance and drug toxicity
An ICD is implanted under the skin, just under the collarbone. It detects arrhythmias and responds with electrical signals to restore your heart's normal rhythm.
Why do I need an ICD?
Your health care team may recommend an ICD if you or your child is at risk of a life-threatening ventricular arrhythmia because of the following:
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• A ventricular arrhythmia
• A heart attack
• Survived a sudden cardiac arrest
• Long QT syndrome
• Brugada syndrome
• Cardiac sarcoidosis
• A congenital heart disease or other underlying conditions for sudden cardiac arrest​​
How is an ICD implanted?
A battery-powered pulse generator is implanted in a pouch under the skin of the chest, often just below the collarbone, or along your ribs. In infants, it may be placed in the abdomen. The generator is about the size of a pocket watch. Wires or leads run from the pulse generator to positions on the surface of or inside the heart and can be installed through blood vessels, eliminating the need for open-chest surgery.
How does an ICD work?
It detects an abnormal heartbeat and tries to return the heartbeat to normal.
If your ICD has a pacemaker feature when your heartbeat is too slow, it works as a pacemaker and sends tiny electric signals to your heart.
When your heartbeat is too fast or chaotic, it gives defibrillation shocks to stop the abnormal rhythm.
It works 24 hours a day.
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Some devices also provide “overdrive” pacing to electrically convert a sustained ventricular tachycardia (fast heart rhythm) and "backup" pacing if bradycardia (slow heart rhythm) occurs. They also offer other functions such as storage of detected arrhythmic events. Stored information can help your doctor optimize the ICD for your needs.
How is an ICD implanted?
A battery-powered pulse generator is implanted in a pouch under the skin of the chest, often just below the collarbone, or along your ribs. In infants, it may be placed in the abdomen. The generator is about the size of a pocket watch. Wires or leads run from the pulse generator to positions on the surface of or inside the heart and can be installed through blood vessels, eliminating the need for open-chest surgery.