Final answer:
An implantable cardioverter-defibrillator (ICD) is a device implanted into the chest that automatically delivers shocks to correct life-threatening arrhythmias like ventricular fibrillation.
Step-by-step explanation:
A device that is implanted into a pectoral subcutaneous pocket and delivers shocks to the heart when ventricular fibrillation is detected is known as an implantable cardioverter-defibrillator (ICD). This life-saving technology is critical for patients who are at risk of sudden cardiac arrest due to ventricular fibrillation or ventricular tachycardia. An ICD is designed to monitor heart rhythms and deliver a shock to the heart when it detects dangerous arrhythmias, thereby reestablishing a normal heart rhythm and preventing potential brain death or damage due to a lack of effective blood circulation.
In the event of a heart attack caused by ventricular fibrillation, which is an emergency situation often coded as "code blue" in hospital settings, quick action is necessary. An ICD functions similarly to other forms of defibrillators, such as Automated External Defibrillators (AEDs), which are found in various public spaces. Both ICDs and AEDs are critical in applying the needed shock to terminate an arrhythmia, but an ICD is an internal device that provides ongoing protection against sudden arrhythmias.