Final answer:
Defibrillation won't revive a heart that has no electrical activity or is too damaged to respond to electrical stimuli. It's most effective in cases like ventricular fibrillation and ventricular tachycardia, where rapid treatment with an AED or manual defibrillator can restore a normal heart rhythm.
Step-by-step explanation:
Defibrillation is not going to revive the heart in cases where there is a complete cessation of electrical activity, also known as asystole, or when the heart has been damaged to the point that it is no longer responsive to electrical stimuli. This medical procedure is designed to treat conditions such as ventricular fibrillation and ventricular tachycardia, where there is still some electrical activity in the heart. Ventricular fibrillation is a particularly serious condition because the heart's ventricles quiver instead of pumping blood, and it may lead to brain death if not treated quickly with defibrillation. Automated external defibrillators (AEDs) have become widespread and can be used by nonmedical personnel, following verbal instructions provided by the device to help save a life. Before using an AED, CPR is often recommended to provide blood flow to the brain and other vital organs. Ultimately, defibrillation works by briefly stopping the heart to allow the sinoatrial (SA) node to reset and establish a normal sinus rhythm.