Return of spontaneous circulation (ROSC) is resumption of sustained perfusing cardiac activity associated with significant respiratory effort after cardiac arrest. Signs of ROSC include breathing, coughing, or movement and a palpable pulse or a measurable blood pressure. Cardiopulmonary resuscitation and defibrillation increase the chances of ROSC.
The return of circulation, while a good thing and a favorable short-term indicator, should not necessarily be seen as a sign of a favorable medium- or long-term outcome, in itself. Patients have died not long after their circulation has returned.
Lazarus phenomenon or autoresuscitation after failed cardiopulmonary resuscitation is the spontaneous return of circulation after resuscitation attempts have stopped in someone with cardiac arrest. Thus passive monitoring is recommended for 10 minutes after resuscitation attempts have stopped.