Similar to the result of tachyarrhthmias, these conditions lead to an inability to sustain adequate blood flow as well, though in the case of bradyarrhthmias, the underlying cause is absence mechanical activity and not rapid beats leading to disorganization. : 837–838

Diagnosis
Cardiac arrest is synonymous with clinical death. Historical information and a physical exam can diagnose cardiac arrest and provide information regarding the potential cause and the prognosis. The provider taking the persons clinical history should aim to determine if the episode was observed by anyone else, what time the episode took place, what the person was doing (in particular if there was any trauma), and if there were involvement of drugs. The physical examination portion of diagnosing cardiac arrest focuses on the absence of a pulse. In many cases, lack of a carotid pulse is the gold standard for diagnosing cardiac arrest. Lack of a pulse in the periphery (radial/pedal) may also result from other conditions (e.g. shock), or simply an error on the part of the rescuer. Studies have shown that rescuers may often make a mistake when checking the carotid pulse in an emergency, whether they are healthcare professionals or lay persons.Point-of-care ultrasound (POCUS) is a tool that can be used to examine the movement of the heart and its force of contraction at the person experiencing cardiac arrests bedside.
According to the American College of Physicians, half-hearted resuscitation efforts are deceptive and should not be performed by physicians or nurses. See also
Chain of survival
Sudden cardiac death of athletes
Post-cardiac arrest syndrome

References
External links

The Center for Resuscitation Science at the Hospital of the University of Pennsylvania