Implantable Cardioverter Defibrillator

What does an automatic implantable cardioverter defibrillator look like? How does it work?

The AICD consists of two parts: first, a box which houses the electronics (the “device”), and second, one or more wires that connect the box to the heart muscle (the “leads”).

This is what an actual AICD looks like. The maximum diameter is around 2 to 3 inches i.e. around the length of your small or ring finger.

Shown here is what a freshly implanted AICD looks like. The incision used to implant the device is around 5 cm long. Usually it is implanted on the left side; occasionally it is implanted on the right side.

Why does my doctor think I need an automatic implantable cardioverter defibrillator?

Your doctor will recommend an AICD if he thinks you are at risk of developing dangerous abnormal heart rhythms (“VT” or “VF”) and therefore at risk of sudden death. This may be because:

• You have already developed VT or VF once before, and are at risk of further episodes of VF or VT
• You have never developed VT or VF before, but your heart muscle function is poor and is therefore prone to developing VT or VF; doctors often measure heart function using a number called the ejection fraction (EF) - you may hear them talking about “poor EF”
• Or you have been diagnosed with one of a number of uncommon syndromes that may predispose you to VT or VF (e.g. Brugada syndrome, long Q-T syndrome, hypertrophic cardiomyopathy, idiopathic VT).

Who and where will the automatic implantable cardioverter defibrillator implantation be done?

A specialist doctor called an Electrophysiologist will perform the procedure. The procedure will be done in the Electrophysiology Lab.

Is automatic implantable cardioverter defibrillator implantation procedure safe?

A device implant is generally a safe procedure. However, as with any invasive procedures, there are risks. Special precautions are taken to decrease your risks.

Your doctor will discuss your risk with you as every individual is different. In general however, the risk of implanting an AICD is low - only 1% or less of serious complications. These include (but are not limited to):

• Infection of the AICD which, if serious, may need removal of the AICD altogether
• Bleeding
  
• Pneumothorax (“collapsed lung”)
• Cardiac perforation
  
• Device malfunction

All of these complications are treatable. However, the most common problem with AICDs is that they may deliver unnecessary shocks; if so, your AICD may need to be re-programmed or your medication altered.

What are the benefits to me if I agree to have an automatic implantable cardioverter defibrillator implanted?

The purpose of the AICD is to protect you from sudden cardiac death due to abnormal heart rhythms; your doctor will normally only recommend one if he thinks this risk substantially outweighs the low risk of AICD implantation.

Are there different types of implantable cardioverter defibrillators?

Yes. Your doctor will determine the best suitable device for you, depending on your condition.