The Lazarus phenomenon is the spontaneous return of a heartbeat after CPR has been stopped and death declared. Anesthesiologist Jack Bray named it in 1993, though medical journals had reported it since 1982, and it appears in the literature at least 38 times. The leading explanation is mechanical: chest compressions build intrathoracic pressure that keeps blood from returning to the heart, and when compressions stop the chest relaxes and blood rushes in, stretching the heart wall and possibly firing its pacemaker cells. Adrenaline pooled in the limbs may also arrive late, and drugs correcting high potassium can take effect after the code ends.

A 27-year-old in the UK who overdosed on heroin and cocaine regained a rhythm one minute after 25 minutes of CPR ended and fully recovered. Others were found alive much later. In 2014, Walter Williams of Mississippi began moving at a funeral home, possibly after his implanted defibrillator fired, and died 15 days later. In 2020, 20-year-old Timesha Beauchamp was declared dead by phone and found breathing at a Detroit funeral home. In 2008, Velma Thomas of West Virginia woke 10 minutes after life support was removed, 17 hours after being declared dead.

• A 66-year-old with a suspected abdominal aneurysm regained a pulse 10 minutes after 17 minutes of resuscitation
• Therapeutic hypothermia slowed Velma Thomas’s metabolism, and her stiffening resembled rigor mortis
• Judith Johnson, 61, of Delaware was found alive after being declared dead in 2007 and sued the medical center
• Long term survival after these events is rare because the original illness remains
• Guidelines now call for five to 10 minutes of passive observation before declaring death