About Implantable Defibrillators

An implantable cardiac defibrillator is (ICD) is about the same size as a pager. It is worn internally to continuously monitor the heart. Like a pacemaker, the ICD can send a signal to a heart that is not beating quickly enough. It can also administer an electric shock to correct a situation where the heart is beating too rapidly.

How an Implantable Cardiac Defibrillator Works

The ICD is positioned in the chest, near the collarbone. Wires connect the device to the heart. The ICD provides continuous monitoring of the heart, and takes steps to correct any abnormalities in the heart rate or rhythm.

Who Needs a ICD?

A person who has or is experiencing irregular heartbeats may be a good candidate for a ICD. Another case where the doctor may recommend a ICD is where the patient has had a heart attack that has damaged the heart’s electrical system. Some patients with congenital heart defects or in heart failure may be outfitted with a ICD as well.

After the ICD is in Place

A patient with a ICD in place will need to have regular follow-up care from his or her primary care physician. Any other doctors or dentists involved in that person’s care should be informed about the ICD.

A person with a ICD implant should carry an ID card indicating this fact. If they require care at a hospital, medical personnel need to be informed before treatment begins.

Having a ICD in place means the individual should stay away from strong magnets. If traveling by air, the person should advise security personnel about the device and request that a hand-held metal detector not be used to screen for hidden devices.

Defibrillators in Public Places Save Lives

When someone goes into cardiac arrest, getting medical help promptly can improve their chance of survival. If defibrillators were installed in more locations where people gather, the patient can get help before the time when they could experience brain damage or die, which is between four and six minutes.

A study released in Circulation on July 29, 2009, found that most cardiac arrests that occurred outside of hospitals occurred in one of these locations:

  • Central Bus Terminals
  • Large Shopping Centers
  • Sports Centers
  • Train Stations

If Automated External Defibrillators, or AEDs, were installed in more public places, as well as schools, then the survival rate for cardiac arrest outside of hospitals would improve. Installing them in areas where large numbers of people meet can save lives. The cost of taking this step seems to be well worth the investment.

Defibrillation: Why CPR is Not Enough

CPR (Cardiopulmonary Resuscitation) is a way to keep blood flowing to the brain and other organs in a person who is in cardiac arrest. Doing so promptly may help to prolong the patient’s life and prevent brain damage from lack of oxygen, but it may not be effective in restoring a pulse. For that, you will need to use a defibrillation machine.

An external defibrillator is a device used to start the heart after it stops beating. It can also be used in a situation where the heart is pumping too quickly and the patient doesn’t have a pulse. The person’s heart may stop beating because its electrical system is not conducting the signals necessary to contract properly. In a situation where the impulses are simply shivering all over the heart, it doesn’t contract strongly enough to produce a pulse.

The defibrillator sends an electric shock that stops the heart temporarily. This only lasts for a moment, with the hope that when the next signal to the heart to start beating will be delivered normally.


Using a defibrillator may not get the patient’s heart to start again, but using one early greatly increases the survival rate for people in cardiac arrest, such as those who have had a heart attack.

If a person goes into cardiac arrest outside of a hospital, their chance of survival is only five percent. However, if that individual is treated using a defibrillator quickly, their chance of surviving the incident goes up to 70 percent. The accent here is on the word quickly: every minute that passes without the person being treated with a defibrillator means that their chance of survival decreases by 10 percent.

This treatment strategy is most successful when performed within five minutes of the start of cardiac arrest. In an emergency where no pulse is detected, start CPR as soon as possible, but make sure that someone calls 9-1-1 or the local emergency number as well. Getting medical personnel who have access to a defibrillator to the scene right away can make the difference between life and death.