The correct answer is D. This patient has WPW, a congenital presence of an accessory conduction pathway between the ventricles and the atria. These patients are prone to reentrant tachyarrhythmias. For this patient, she is in a pulseless ventricular tachycardia/ventricular fibrillation pathway of the ACLS algorithm and should be managed in that manner. The sequence is airway, breathing, chest compressions, and synchronized cardioversion to avoid the R on T phenomenon and precipitate ventricular tachycardia or asystole.
Intravenous amiodarone (choice A) has been shown to be superior to lidocaine in the management of pulseless VT/VF after cardioversion or countershock and epinephrine. It has taken a class IIb indication (demonstrated benefit) in these scenarios. It is also used as an adjunct to electrical cardioversion of reentrant ventricular tachycardia.
Metopolol (choice B) is a beta-1 specific antagonist used for rate control in hemodynamically stable atrial and ventricular tachycardias. This patient is not hemodynamically stable.
Verapamil (choice C) should be avoided in patients with WPW. Verapamil, diltiazem, and digitalis (drugs that slow AV nodal conduction) can cause a paradoxical increase in ventricular rates by facilitating preferential conduction through the accessory pathway.
Unsynchronized cardioversion (choice E) is inappropriate because of the presence of an electrical QRS complex that can be synchronized with the defibrillator.
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