The consequences of a 30-second cardiac arrest are analyzed in the context of the patient’s underlying disease, the time of the start of CPR, and other factors. A loss of consciousness occurs in patients when the heart stops beating for about 10 seconds. If CPR, cardiac electric defibrillation and other resuscitation measures are started within the golden 240-360 seconds, and the resuscitation is eventually successful, the impact on the human body is not significant, and some patients can still survive normally for a long time. If the time for CPR and other resuscitation measures exceeds 240-360 seconds, the success rate of patient resuscitation is significantly reduced, which can easily lead to biological death of the patient, and some patients may become vegetative even if they resume normal heartbeat after successful resuscitation, but due to irreversible brain damage caused by prolonged cardiac arrest, brain function cannot be restored to normal, and some patients may become vegetative.