What is a defibrillator (ICD device)?
An implantable cardioverter defibrillator (ICD) is a small device that treats abnormal heart rhythms called arrhythmias. Specifically, an ICD treats fast arrhythmias in the heart's lower chambers (ventricles). Two such arrhythmias are ventricular tachycardia (VT), and ventricular fibrillation (VF).
Arrhythmias result from a problem in your heart's electrical system. Electrical signals follow a certain path through the heart. It is the movement of these signals that cause your heart to contract.
During VT OR VF, however, far too many signals are present in the ventricles. In addition, the signals often do not travel down the proper pathways. The heart tries to beat in response to the signals, but it cannot pump enough blood out of your body. If you have either VT or VF, you are at high risk of sudden cardiac arrest (SCA). If not treated immediately with defibrillation, SCA can result in sudden cardiac death (SDC).
An ICD can treat VF OR VT, and restore your heart to a normal rhythm - so it reduces your risk of SCD. That device can deliver several types of treatment:
- Anti-tachycardia pacing (ATP) delivers very small amounts of energy to your heart- so small that you can't feel the treatment.
- Cardioversion is a low-energy shock that treats fast but regular arrhythmias.
- Defibrillation is a high -energy shock that treats fast and chaotic (irregular) rhythms. Defibrillation is painful of a instant, but it can also save your life.
A device implant is a procedure that uses local numbing. General anesthesia is usually not needed.
How is the implant procedure done?
An implantable cardioverter defibrillator (ICD) system has two parts.
Device- the device is quite small and easily fits in the palm of your hand. It contains small-computerized parts that run on a battery.
Leads- the leads are thin, insulated wires that connect the device to your heart. The leads carry electrical signals back and forth between your heart and your device.
Your doctor inserts the leads through a small incision, usually near your collarbone. Your doctor gently steers the leads through your blood vessels and into your heart. Your doctor can see where the leads are going by watching a video screen with real time, moving x-rays called fluoroscopy.
The doctor connects the leads to the device and test to make sure both work together to deliver treatment. Your doctor then places the device just under your skin near the collarbone, and stitches the incision closed.
What can I expect?
Usually you are told not to eat or drink anything for a number of hours before the procedure. You undress and put on a hospital gown or sheet. Your procedure will be performed in a "cath lab." You lie on an exam table, and an intravenous line (IV) is placed into your arm. The IV delivers fluids and medications during the procedure. The medicine makes you groggy, not unconscious.
The doctor makes a small incision near your collarbone to insert the leads. The area will be numbed so you don't feel pain, but you may feel some pressure as the leads are inserted. You may be sedated when the device is tested, since it delivers a shock to your heart.