Approximately 850,000 people in the United States are at risk of sudden cardiac arrest and indicated for an implantable defibrillator device, but remain unprotected.   Thuy Le, M.D., a board-certified cardiac electrophysiologist at The MemorialCare Heart & Vascular Institute at Orange Coast Memorial Medical Center, discusses the recent advances in implantable defibrillators, who would benefit from the device and how it works to save lives.