Overview
Cardiac arrest, also known as sudden cardiac arrest, is when the heart suddenly and unexpectedly stops beating. As a result blood will not be pumped around the body in normal circulation, consciousness will be rapidly lost, and breathing will be abnormal or absent. Without immediate intervention such as cardiopulmonary resuscitation (CPR), and possibly defibrillation, death will occur (sudden cardiac death) within minutes.
The most common cause of cardiac arrest is an irregular heart rhythm (arrythmia), usually ventricular fibrillation (V-fib), or ventricular tachycardia (V-tach). Heart problems are the main risk factor.
Less common causes include major blood loss, lack of oxygen, very low potassium, electrical injury, heart failure, inherited arrhythmias, and intense physical exercise. Cardiac arrest is diagnosed by the inability to find a pulse.
CPR and defibrillation can reverse a cardiac arrest, leading to the return of spontaneous circulation (ROSC), but without such intervention, it will prove fatal, known as sudden cardiac death. In some cases, cardiac arrest is an anticipated outcome of serious illnesses where death is expected. Treatment for cardiac arrest includes immediate CPR and, if a shockable rhythm is present, defibrillation. Two protocols have been established for CPR: basic life support (BLS) and advanced cardiac life support (ACLS). Among those whose pulses are re-established, targeted temperature management may improve outcomes. In addition, the care team may initiate measures to protect the patient from brain injury and preserve brain function. In post-resuscitation care, an implantable cardiac defibrillator may be considered to reduce the chance of death from recurrence.
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