According to the National Heart Lung and Blood Institute, each year between 250,000 and 450,000 Americans-mostly between the ages of the mid-30s and the mid-40s-have sudden cardiac arrest (SCA), a condition in which the heart suddenly stops beating. Because SCA causes blood to stop flowing to the brain and other vital organs, death can occur within minutes-95 percent of SCA sufferers will die from it-which is why rapid treatment with a defibrillator is so important. Automated external defibrillators, which are usually found in public places, such as airports and office buildings, can be lifesaving when used promptly because they can send an electrical shock to the heart, restoring its normal rhythm.

For people with a history of abnormal heart rhythms, either too slow (bradycardias) or too fast (tachycardias), having an implantable cardiac defibrillator (ICD) can also be lifesaving because it can detect any dangerous heart arrhythmia and deliver an electrical shock to restore the heart's normal rhythm and prevent sudden cardiac death.

How ICDs Work

An implantable cardiac defibrillator is a small (about the size of a pacemaker) electronic device that's installed inside the chest and consists of one or more leads (wires) and a defibrillator unit. The leads are used to deliver electrical shocks to the heart, sense dangerous cardiac arrhythmias and pace the heart as needed. The latest devices are so small and simple, they can be implanted via blood vessels, eliminating the need for open chest surgery.

Should You Have an ICD?

If you have a history of abnormal heart rhythms, talk to you doctor about whether an ICD is right for you. Some recent clinical trials have identified certain groups of people most likely to benefit from an ICD. They include:

  • People who have survived cardiac arrest
  • People with ventricular tachycardias that significantly decrease the amount of blood delivered by the heart, resulting in low blood pressure
  • People with significant heart muscle damage due to a prior heart attack and have ventricular tachycardia episodes that are not helped by medications
  • People at high risk for sudden cardiac death based on their history of heart disease and the results from an electrophysiology study (EPS), which tests the electrical system of the heart

Preventing Sudden Cardiac Death

Living a heart-healthy lifestyle can help reduce your chances of becoming a victim of sudden cardiac arrest or other heart conditions. They include:

  • Getting regular exercise
  • Eating healthful foods
  • Maintaining a healthy weight
  • Quitting smoking;