What best describes the use of an electrical shock through pads attached to the chest to restore life-threatening heart conditions?

• A. Internal Defibrillation
• B. Pacemaker Therapy
• C. External Defibrillation
• D. Cardioversion

Answer: (C)

External defibrillation uses pads placed on the chest to deliver a high-energy electrical shock from an outside device. The shock aims to depolarize a critical portion of the heart muscle, interrupting the chaotic electrical activity seen in life-threatening rhythms like ventricular fibrillation or pulseless ventricular tachycardia, so the heart’s natural pacemaker can regain control and restore a viable rhythm with a pulse. This is different from internal defibrillation, which uses implanted hardware inside the chest; pacemaker therapy, which paces the heart rather than shocks; and cardioversion, which delivers a synchronized shock to a heart with a pulse. In a pulseless arrest, the unsynchronized shock delivered externally is the appropriate intervention.