Cardiac arrest is a critical medical emergency characterized by the sudden cessation of heartbeat and blood circulation. It can be caused by a cardiac electrical event such as when the heart rate is too fast (tachycardia) or slow (bradycardia) or when there is no heart rate at all (asystole). Cardiac arrest may follow a respiratory arrest. It may also occur when electrical activity is present but there is ineffective cardiac contraction or circulating volume which is called pulseless electrical activity (PEA). PEA can be caused by hypovolemia, cardiac tamponade, medication overdoses, significant acidosis, etc. This article highlights the various causes, symptoms, and management strategies for cardiac arrest, emphasizing the importance of immediate action to improve survival outcomes.
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What is Cardiac Arrest

Cardiac arrest is a sudden cessation of the heartbeat. It occurs when the heart ceases to produce an effective pulse and blood circulation.

Causes of Cardiac Arrest

  • Ventricular fibrillation
  • Progressive profound bradycardia, AV block
  • When there is no heart rhythm at all (asystole)
  • Respiratory arrest
  • Hypovolemia
  • Hypoxia and hyperkalemia
  • Massive pulmonary embolism
  • Myocardial infarction
  • Medication overdose (beta blockers and calcium channel blockers)

Clinical features of Cardiac Arrest

  • The most reliable sign of cardiac arrest is the absence of pulse
  • Consciousness, pulse and blood pressure are lost immediately
  • Ineffective respiratory gasping
  • Pupils of the eyes begin to dilate within 45 seconds
  • Seizures may or may not occur
  • Irreversible brain damage

Management of Cardiac Arrest

  • Pulmonary resuscitation or CPR
  • The ABCDs of basic cardiopulmonary resuscitation