Which arrhythmia requires immediate defibrillation?

• A. A-fib
• B. A-flutter
• C. Pulseless v-tach
• D. V-fib

Answer: (D)

Ventricular fibrillation is an uncoordinated, chaotic electrical activity in the ventricles that produces no effective heartbeat and no pulse. Because the heart isn’t pumping, immediate defibrillation is the only rapid way to try to reset the electrical activity and restore a viable rhythm. In this situation, CPR should begin right away while the defibrillator is prepared, and a shock is delivered as soon as possible.

Understand that other rhythms are treated differently. Atrial fibrillation or atrial flutter, even though irregular, involve some organized atrial activity and are typically managed with rate control and, if needed for instability, synchronized cardioversion rather than immediate unsynchronized defibrillation. If a ventricular rhythm is pulseless but organized (pulseless ventricular tachycardia), defibrillation is still indicated, but the classic teaching emphasis for the “requires immediate defibrillation” scenario is the chaotic ventricular activity seen in ventricular fibrillation.