What is an implantable cardioverter-defibrillator (ICD)?

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An implantable cardioverter-defibrillator is a device that fixes an erratic heart rate or rhythm and prevent sudden death. This battery-powered device is inserted within the chest that is affixed to one or two wires that go into the heart via a vein.


One might require an implantable cardioverter-defibrillator if he/she has experienced a serious episode of an erratically rapid heart rhythm or at high risk for developing one. In case an individual has heart failure, coronary heart disease or issues with the electrical or structural system of the heart, he/she is at risk for an erratic heart rhythm.

How does it work?

An implantable cardioverter-defibrillator is constantly monitoring the heart rate and rhythm. Once it detects a life-threatening fast heart rhythm, it attempts to slow it down to the normal rate.

Implantable cardioverter-defibrillator
An implantable cardioverter-defibrillator is constantly monitoring the heart rate and rhythm.

It can also restore a heart rate that is too rapid or slow. This is done by transmitting electrical pulses to hasten the heart rate that is too slow. If the heart rate is too fast, it can slow it down by matching the pace and restoring the normal rate.

Placement of an implantable cardioverter-defibrillator

The doctor sets the implantable cardioverter-defibrillator in the chest during a minor surgery that might require local anesthesia. Medications that relaxes and causes sleepiness might also be given.

The doctor creates a small-sized incision in the upper chest and inserts one or two wires in a vein and wind them to the heart. These wires are connected to the device. The doctor programs the device and sets it in the chest and closes the incision.

In most cases, the individual must stay overnight in the healthcare facility to ensure that the device is functional and there are no issues from the surgery.

How does a shock feel like?

The shock from an implantable cardioverter-defibrillator can cause brief discomfort. This can be described as a punch in the chest but this shock is an indication that the device is doing its task in keeping the heart beating. The individual will not feel any pain if the device utilizes electrical pulses to fix a heart rate that is too slow or fast.

More Information / Disclaimer

The information posted on this page on an implantable cardioverter-defibrillator is for learning purposes only. Learn more about an implantable cardioverter-defibrillator by taking a standard first aid course with one of our training providers.

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