The latest on implantable cardioverter defibrillators (ICDs)

In previous posts, we’ve touched on portable automatic external defibrillators (AEDs) and how they are become popular and invaluable in saving lives. This post is about ICDs – implantable cardioverter defibrillators.

What are ICDs?

An ICD is a battery-operated implanted device that is designed to detect abnormal heart rhythms (arrhythmia) and apply corresponding electrical jolt to set the rhythm right.

According to Arrhythmia Alliance, a UK-based charity organization, most modern ICDs function in 3 ways:

If your heart rhythm is too slow, the device can give your heart extra beats by working as a normal pacemaker. This is called anti-bradycardia pacing

If your heart beats too fast, the ICD can give you a burst of extra beats at an even faster rate which will normally return your heart back to a normal rhythm. This is called anti-tachycardia pacing (or ATP)

If the anti-tachycardia pacing doesn’t bring your heart back to a normal rhythm, or if the ICD senses a faster rhythm called ventricular fibrillation, the ICD can then give a higher energy shock. This is called defibrillation

Is an ICD really necessary?

According to a recent article in the New York Times, ICDs are becoming less popular because the risks seem to outweigh the benefits. The article concedes that ICDs have saved thousands of lives since its introduction in 1985. This study published in the New England Journal of Medicine observed that simple, shock-only ICD therapy actually improves survival better compared to state-of-the-art drugs like amiodarone in patients with congestive heart failure.

However, the product has been plagued by technical problems that led to highly publicized recalls that even led to deaths. There are also studies which seem to indicate that the majority of people with ICDs don’t actually need it. In other words, ICDs are stand-by devices that the patients may not actually need.

However, there are people who actually need ICDs in order to live a normal life. According to the Amerian Heart Association, ICDs are “used in patients at risk for recurrent, sustained ventricular tachycardia or fibrillation.”

More information about ICDs

It is a tough choice to make – would you want to have a device implanted in you even though you might not actually need it. According to the NYT article, the chance of an ICD saving a patient’s life is about 1 in 14, over a 5-year period. Which way do you bet?

If you want you want to know more ICDs and whether you or your loved one needs one, then inform yourself about ICDs by clicking on the following resources:

The Role of Implantable Defibrillators in Preventing Death from Cardiac Arrest (video)

Implantable Cardioverter Defibrillator (ICD) Animation

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