An implantable cardioverter defibrillator (ICD) is a device similar to a pacemaker, which is usually placed under the skin below your collarbone.
ICDs are often used as a preventative treatment for people thought to be at risk of cardiac arrest at some point in the future.
ICD senses if the heart is beating at a potentially dangerous abnormal rate and delivers an electrical shock to the heart that essentially “reboots” it to return to a normal rhythm and start pumping again.
Most modern ICDs have three main functions:
- If your heart rhythm is too slow, the device can give your heart extra support by working as a normal pacemaker (anti-bradycardia pacing).
- If your heart beats too fast, the ICD can return your heart back to a normal rhythm (anti-tachycardia pacing or ATP).
- If the anti-tachycardia pacing does not bring your heart back to a normal rhythm, or if the ICD senses a faster, dangerous rhythm called ventricular fibrillation, the ICD can then give a shock (defibrillation) to the heart to restore normal rhythm.
What does the procedure involve?
In most cases, implantable cardioverter defibrillators (ICDs) are fitted transvenously, along a vein. But they can also be fitted under the skin (subcutaneously). Subcutaneous implantation is either carried out using general anaesthesia, or with local anaesthesia and sedation.
- During the procedure, a pocket will be created in the left side of the chest where the ICD will be positioned.
- The pacing lead and electrodes are also placed under the skin along the breastbone and are connected to the device.
- After the cuts have been closed, the sensing, pacing and recording functions of the ICD will be tested and adjusted.
Fitting an ICD can take 1 to 3 hours depending on the type of device you’re having fitted. An overnight stay in the hospital is often, although not always, required.
References:
- https://www.hey.nhs.uk/patient-leaflet/defibrillator-icd-implantation/
- https://www.nhs.uk/conditions/pacemaker-implantation/#:~:text=Implantable%20cardioverter%20defibrillators%20(ICDs)&text=ICDs%20are%20often%20used%20as,electrical%20shock%20to%20the%20heart.
- https://www.nhs.uk/conditions/pacemaker-implantation/what-happens/