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More Than Fancy Pacemakers: How ICDs Help You

Implantable Cardiac DefibrillatorsWhen you’re at risk of sudden cardiac death, one small device can save your life. That’s the implantable cardioverter-defibrillator (ICD).

“People often describe ICDs as fancy pacemakers, but they’re much more than that,” says cardiologist Bruce Wilkoff, MD, an arrhythmia specialist.

The pacemaker delivers 60, 80 or 100 imperceptible, low-energy electrical impulses per minute to keep a slow heart beating normally. The ICD delivers high-energy electrical impulses only during life-threatening arrhythmias to shock the heart back into normal rhythm.

The ICD — about twice as big as the tablespoon-sized pacemaker — is similarly implanted under the skin near your shoulder and connected to the heart by wires called leads.

A matter of life and death
When the heart’s pumping chambers, or ventricles, start beating too fast (tachycardia) or quivering (fibrillation), the heart can’t pump much blood. “You pass out within five to 10 seconds, and if you’re not rescued with an automated external defibrillator (AED) within 10 minutes, the brain dies,” says Dr. Wilkoff.

Ninety-five percent of cardiac arrest episodes are fatal because:

  • The person is alone when it occurs.

  • Bystanders don’t know how to use an AED.

  • Bystanders don’t call 911 soon enough, or the emergency squad is too far away.

But once a defibrillator is implanted in your heart, your odds of survival jump to 98 or 99 percent. That’s because when an episode occurs, the ICD automatically delivers a shock to restart your heart within seconds.

Who needs an ICD?