Cardiac arrest

A medical emergency with absent or inadequate contraction of the left ventricle of the heart that immediately causes bodywide circulatory failure. The signs and symptoms include loss of consciousness; rapid shallow breathing progressing to apnea (absence of breathing); profoundly low blood pressure (hypotension) with no pulses that can be felt over major arteries; and no heart sounds. Cardiac arrest is one of the greatest of all medical emergencies. Within several minutes, there is lack of oxygen (tissue hypoxia), leading to multiple organ injury. Unless cardiac arrest is quickly corrected, it is fatal. The most common causes of cardiac arrest are electrical problems in the heart with ventricular fibrillation representing the major type. In ventricular fibrillation, there is loss of coordinated ventricular contractions leading to immediate loss of effective output of blood by the heart, resulting in circulatory arrest.

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cardiac arrest n abrupt temporary or permanent cessation of the heartbeat (as from ventricular fibrillation or asystole) called also sudden cardiac arrest

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the cessation of effective pumping action of the heart, which most commonly occurs when the muscle fibres of the ventricles start to beat rapidly without pumping any blood (ventricular fibrillation) or when the heart stops beating completely (asystole). There is abrupt loss of consciousness, absence of the pulse, and breathing stops. The most common cause is myocardial infarction. Unless treated promptly, irreversible brain damage and death follow within minutes. Some patients may be resuscitated by massage of the heart, artificial respiration, and defibrillation.

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sudden cessation of the pumping function of the heart, with disappearance of arterial blood pressure, connoting either ventricular fibrillation or ventricular standstill; it usually leads to death unless corrected but may be temporary or paroxysmal.