Cardioversion or DEFIBRILLATION, is indicated in patients with ventricular fibrillation or tachycardia (fast or irregular heartbeat) if other treatments have failed. A general anaesthetic is given if the patient is conscious, following which a carefully timed direct-current shock is applied to the patient's chest wall using a DEFIBRILLATOR. The patient's ECG rhythm should then be monitored and anticoagulants considered, as the risk of EMBOLI is increased.