What is the electrical therapy that stops arrhythmias and allows the heart to reestablish an effective rhythm?

• A. Pacing
• B. Defibrillation
• C. Cardioversion
• D. Resuscitation

Answer: (A)

In electrical therapies for arrhythmias, the goal is to halt the abnormal electrical activity and let the heart reset to a normal rhythm. The treatment that accomplishes this by delivering a high-energy, unsynchronized shock to terminate chaotic activity (like ventricular fibrillation or pulseless ventricular tachycardia) and allow the heart to resume an effective rhythm is defibrillation.

Pacing, in contrast, provides ongoing electrical impulses to maintain a suitable heart rate when the heart’s natural pacing is too slow or blocked, but it doesn’t stop an existing arrhythmia. Cardioversion also aims to stop an abnormal rhythm, but it uses a synchronized shock timed to the heartbeat to convert the rhythm to a normal one; it’s used for rhythms like atrial fibrillation with a pulse or unstable tachycardias. Resuscitation is a broader set of life-support actions, not an electrical therapy by itself.