When are AEDs beneficial?

AEDs automatically check the victim's heart rhythm and determines if a shock may correct it. Defibrillation is particularly successful on a rhythm known as ventricular fibrillation, or v-fib. V-fib means that the ventricles of the heart are beating very fast, or quivering. The AED may help return the heart to a normal rhythm. The faster that an AED is used on a victim, the greater the chance of survival.