Definition of Defibrillator, implantable cardiac

Defibrillator, implantable cardiac: A device that is designed to be put in the body to recognize certain types of abnormal heart rhythms (arrhythmias) and correct them by delivering precisely calibrated and timed electrical shocks to restore a normal heartbeat. Defibrillators continuously monitor the heart rhythm in order to detect overly rapid life-threatening arrhythmias, such as ventricular tachycardia (rapid regular beating of the ventricles, the bottom chambers of the heart) or ventricular fibrillation (rapid irregular beating of the ventricles).