Harvard Heart Letter
What is an implanted cardioverter-defibrillator, and who needs one?
Learn how these high-tech devices can save — and change — your life. Defibrillators are devices that can detect — and correct — potentially deadly heart rhythms. The most common is ventricular fibrillation, which makes the heart’s lower chambers (ventricles) quiver without actually squeezing and pumping. Blood stops flowing to the brain and other organs, causing the person to pass out. Death can occur within minutes.