Which medication may be used for shock-refractory VF or pVT?

Amiodarone is indicated for the management of shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT). This antiarrhythmic medication is effective in stabilizing the cardiac rhythm following defibrillation attempts that have not been successful. Its mechanism involves prolonging the action potential duration and refractory period in myocardial tissue, which helps to restore normal heart rhythm when sustained arrhythmias have not responded to initial therapies.

When treating VF or pVT that does not respond to defibrillation, the administration of amiodarone can enhance the likelihood of converting these lethal rhythms to a normal sinus rhythm, making it a critical drug in advanced cardiac life support protocols. The use of this medication should be in conjunction with other recommended interventions, such as chest compressions and defibrillation.

In contrast, while epinephrine plays a role in vasoconstriction and could potentially increase coronary perfusion pressure during CPR, it is not specifically effective for the rhythm management of shock-refractory VF or pVT. Atropine is primarily used for symptomatic bradycardia and not indicated for VF or pVT. Sodium bicarbonate is not routinely recommended in the immediate management of these specific arrhythmias