Lazarus syndrome

Lazarus syndrome (the Lazarus heart), also known as autoresuscitation after failed cardiopulmonary resuscitation, is the spontaneous return of a normal cardiac rhythm after failed attempts at resuscitation. It is also used to refer to the spontaneous return of cardiac activity after the patient has been pronounced dead. The phenomenon was first described in medical journals in 1982, and has been noted at least 38 times since then. It was named the "Lazarus Phenomenon" by Jack G. Bray in 1993, referring to Lazarus of Bethany who, according to the New Testament, was raised from the dead by Jesus.

Occurrences of the syndrome are extremely rare, and the causes are not well understood. One hypothesis for the phenomenon is that a chief factor (though not the only one) is the buildup of pressure in the chest as a result of cardiopulmonary resuscitation (CPR). The relaxation of pressure after resuscitation efforts have ended is thought to allow the heart to expand, triggering the heart's electrical impulses and restarting the heartbeat. Other possible factors are hyperkalemia or high doses of adrenaline.