Implantable Cardioverter Defibrillator (ICD)
An Implantable Cardioverter Defibrillator (ICD) is a small, battery powered, pager size device.
- Ventricular tachycardia (when the lower chambers of the heart independently beat faster than 100 beats per minute)
- Ventricular fibrillation (when the muscle fibers of the lower chambers of the heart contract in a fast, uncoordinated manner)
- Sudden cardiac death caused by arrhythmias
Once the ICD is implanted, the leads monitor the heart rate. If the ICD detects ventricular tachycardia or fibrillation, it sends out a controlled burst of impulses (called "overdrive" pacing). If this does not work, the ICD "shocks" the heart
to restore a normal rhythm. ICDs are very effective in preventing sudden deaths and can be implanted with a low rate of complications.
A defibrillator is made up of two parts:
- A pulse generator, which includes the battery and several electronic circuits
- Wires, called leads that are attached to the heart wall. Depending on the type of ICD, you may have one to three leads.
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