Implantable Cardioverter Defibrillator

An implantable cardioverter defibrillator (ICD) is an electronic device that is implanted under the skin, and is used to detect an abnormal heartbeat. An ICD is often implanted in individuals with arrhythmias (irregular heartbeats). This device uses electrical impulses to control dangerous arrhythmias that may lead to heart attack or sudden cardiac arrest. If an abnormal heartbeat is detected, the ICD will deliver an internal electric shock to the heart, restoring a normal heart beat as needed.

Candidates for an ICD

Individuals at risk for ventricular arrhythmia may include people who have:

  • Had a heart attack
  • Experienced cardiac arrest
  • Congenital heart disease
  • Brugada syndrome
  • Existing ventricular arrhythmia

When ventricular arrhythmias occur, the heart cannot properly pump the blood. This may cause a person to lose consciousness within seconds and die within minutes if not treated. The ICD can prevent life-threatening ventricular arrhythmias with an electric shock to the heart.

How an ICD Works

An ICD is a small, battery-operated device that is implanted under the skin, below the left collarbone, to help maintain a regular heartbeat. The ICD sends electronic signals to the heart to help it pump properly when needed. The ICD consists of two flexible parts: the lead and the pulse generator. The lead monitors and treats the heart, while the generator contains a battery and tiny computer. When a very fast or abnormal heart beat is detected, the ICD sends energy to the heart to shock it and help it return to a normal rhythm.

The ICD Implantation Procedure

A cardioverter defibrillator is surgically implanted and the procedure is performed in a hospital. A small incision is made under the collarbone, and the lead is placed in a vein and led to the heart chamber, while the generator remains attached to it and is placed under the skin of the upper chest. After the ICD is implanted, the doctor programs it to treat the individual's specific heart rhythm problem.

Considerations of ICD Implantation

Although rare, complications of an ICD implant may include infection, bleeding, damage to veins or puncture of the heart or lung. Patients should avoid strong electric or magnetic fields after the implantation of the cardioverter defibrillator. An ICD battery lasts an average of 7 to 10 years and should be checked regularly and replaced by a doctor when necessary.

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