In cardiac arrest with a shockable rhythm, what should be done promptly?

• A. Defibrillate as soon as a shockable rhythm is identified
• B. Start CPR for two minutes before shocking
• C. Administer vasopressors before defibrillation
• D. Check for a pulse for 60 seconds

Answer: (A)

Prompt defibrillation is essential when a shockable rhythm is detected in cardiac arrest. The heart's chaotic electrical activity in rhythms like ventricular fibrillation or pulseless VT responds best to an immediate shock, which can reset the electrical pattern and restore a usable heartbeat. Delaying the shock by performing prolonged CPR first or other steps reduces the chance of survival because the myocardium remains in a disorganized state that is less likely to convert to a perfusing rhythm. After the shock is delivered, resume CPR right away and continue with the rest of the resuscitation steps as guided. Vasopressors belong after the initial defibrillation, and checking for a pulse for a long period during arrest isn’t the priority when a shockable rhythm is present.