Final answer:
Unsynchronized cardioversion, or defibrillation, is used for life-threatening conditions like ventricular fibrillation, which is an emergency scenario requiring immediate treatment to prevent brain death and restore normal sinus rhythm.
Step-by-step explanation:
Unsynchronized cardioversion (defibrillation) should only be used with ventricular fibrillation or pulseless ventricular tachycardia where the situation is a life-threatening medical emergency that requires immediate intervention.
Defibrillation involves the delivery of a large electrical charge via paddles or pad electrodes placed on the chest to interrupt chaotic heart rhythms. Especially in cases of ventricular fibrillation, where the heart beats in an uncontrolled manner and fails to pump blood effectively, defibrillation stops the heart momentarily. This allows the sinoatrial (SA) node, the natural pacemaker, to regain control and establish a normal sinus rhythm.
The use of Automated External Defibrillators (AEDs) has become widespread, found in public places like schools and airports, and designed for use by nonmedical personnel with verbal instructions provided by the device. AEDs automatically diagnose the condition of the heart and deliver an appropriate shock, if necessary. Furthermore, Cardiopulmonary resuscitation (CPR) is recommended before defibrillation to increase the chances of a successful resuscitation.