Administration of one or more brief electric shocks to the heart, usually via 2 metal plates, or paddles, placed on the chest over the heart. It is performed to return a heart’s rhythm to normal in some types of arrhythmia (irregular or rapid heartbeat), such as atrial fibrillation or ventricular fibrillation. Defibrillation can be carried out as an emergency procedure to treat ventricular fibrillation, which is a cause of cardiac arrest and most commonly occurs after a heart attack (see myocardial infarction). It can also be used as a planned treatment, in which case it is performed under a brief general anaesthesia. Breathing may be maintained artificially during the procedure.


Online Medical Dictionary: Your essential reference to over 5000 medical terms.