Which rhythm is most commonly associated with sudden cardiac arrest?

• A. Asystole
• B. Pulseless Electrical Activity
• C. Ventricular Fibrillation (V-FIB)
• D. Ventricular Tachycardia

Answer: (C)

Ventricular fibrillation is the rhythm most commonly linked to sudden cardiac arrest. It’s a chaotic, disorganized electrical activity in the ventricles that produces no effective heartbeat or pulse. On a monitor, you’d see no recognizable P waves or organized QRS complexes, just rapid, irregular activity. Because there’s no coordinated contraction, blood isn’t being pumped, which is why immediate defibrillation is essential, followed by high-quality CPR and rapid rhythm correction.

In contrast, asystole is a flatline with no electrical activity, and pulseless electrical activity shows electrical signals but no sufficient mechanical contraction—both are non-shockable and have a poorer prognosis. Ventricular tachycardia can cause arrest if the patient is pulseless, and is treated with defibrillation when appropriate, but the initial rhythm most commonly associated with sudden cardiac arrest remains ventricular fibrillation.