Defibrillation may be performed for which rhythm?

• A. Atrial Fibrillation
• B. Ventricular Fibrillation
• C. Torsades de Pointes
• D. Asystole

Answer: (B)

Defibrillation is used for shockable rhythms—rhythms in which there is chaotic electrical activity and little to no effective cardiac output. Ventricular Fibrillation fits this scenario: the ventricles quiver, there’s no organized contraction, and there is typically no pulse. A rapid unsynchronized shock can reset the electrical activity and allow a return to a usable rhythm.

Atrial Fibrillation is an atrial rhythm and is not treated with defibrillation as a first-line approach; unstable AF may require synchronized cardioversion, not the unsynchronized shock used for VF. Asystole is a straight line with no electrical activity and is non-shockable—treatment is CPR and medications. Torsades de Pointes can be shockable if the patient is pulseless, but the classic rhythm for immediate defibrillation is ventricular fibrillation.