Cardiac arrest - the sudden failure of the heart to pump blood - claims 200,000 to 400,000 lives each year in the United States. The most common causes of cardiac arrest are two heart-rhythm disorders.

Anna Lou Sonderman says that her husband "He passed out one night. I went out in the kitchen I heard him fall and he didn't realize what had happened."

Cardiologist Steven Longobardi explains that an abnormal heart rhythm can have a debilitating affect on a patient. But the implantible defibrillator can change all of that for some patients. "It senses the hearts rhythms at all times, 24 hours a day, every minute. It senses a bad heart rhythm, which can lead to death.

Defibrillator patient Doug Sonderman says, "When they put the defibrillator in, it controls the beating of my heart 100% of the time."

Doug also says that it's a type of artificial pacemaker designed to resynchronize the left and right ventricle and so that they beat in synch. "The defibrillator will just jolt me if it stops."

Dr. Longobardi says that the defibrillator uses batteries to send electric signals to a heart that's beating too slow, same as a pacemaker "The patient will receive a shock, an electrical shock which restores the heart rhythm back to normal."

This device helps to save lives but it is not a cure. Patients with congestive heart failure still need to make commitments to healthy lifestyle changes.

The defibrillator can decrease deaths in people with weak hearts by more than 30%.