What is an implantable cardioverter-defibrillator (ICD)?

An implantable cardioverter-defibrillator (ICD) is an electronic device that tracks the heart rate and restores a normal rhythm if required. It is the first-line treatment for patients who are at risk of sudden cardiac death. ICD is useful in reducing the death rate amongst patients suffering from:
- Cardiac arrest
- Heart failure
- Reduced ejection fraction (reduced amount of blood pumped out of heart’s chambers)
- Specific structural heart diseases
Why do I need an ICD?
ICD is recommended if you had the following conditions:
- Life-threatening abnormal heart rhythm or risk of having it
- Genetic disorders that affect the heart such as cardiomyopathy, Brugada syndrome, or Long QT syndrome
- Heart failure previously
- Cardiac arrest
- Congenital heart disease
How does an ICD work?
It detects and corrects the abnormal rhythm of the heart. It works 24 hours a day. ICD works in the following ways:
- For slow heartbeats, it works as a pacemaker (to help control abnormal heart rhythms) and sends small signals to the heart.
- For faster heartbeats, it sends one or more large shocks (defibrillation) to correct the abnormal rhythm.
- New devices of ICD offer sophisticated functions and better control of heartbeats.
How long can you live with an implanted defibrillator?
You need to live with an ICD for the rest of your life. Hence, it is important to have regular check-ups and monitoring every three months to ensure the proper functioning of an ICD. You can resume a near-normal lifestyle.
You have to be aware of machines or activities that can affect your ICD (e.g., airport security machines or TENS (transcutaneous electrical nerve stimulation) machines. Machines with strong magnetic fields can disturb an ICD.
Ask your physician regarding the dos and don’ts after an ICD implantation.
What are the side effects of a defibrillator?
The side effects of placing an ICD are:
- Arteriovenous fistula (an abnormal connection between the artery and the vein)
- Blood clots in the arteries or veins
- Injury to the lung, a collapsed lung, or bleeding in the lung cavities
- Developing a hole in the blood vessels
- Infection of the system
- Bleeding from the pocket
- Death
- High defibrillation shock or failure to defibrillate
- Rejection phenomena
- Oversensing or undersensing the heartbeats can lead to shocks or failure in treatment respectively
- Surgical complications at the incision site such as bleeding, infection, inflammation, and blood clots
- Obstruction of the major vein (superior vena cava) of the heart

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