The cessation of effective pumping action of the heart. This may be because the heart stops beating altogether (asystole), because there is normal electrical activity without mechanical pumping activity (pulseless electrical activity), or because there is rapid, chaotic, ineffective electrical and mechanical activity of the heart (ventricular fibrillation or ventricular tachycardia). There is abrupt loss of consciousness, absence of the pulse, and breathing stops. Unless treated promptly, irreversible brain damage and death follow within minutes. Some patients may be resuscitated by airway clearance and support, artificial ventilation, massage of the heart, and (if ventricular fibrillation or tachycardia is present) defibrillation.
Subjects: Medicine and Health.