Emergency Medical Minute

Contributor: Aaron Lessen, MD Educational Pearls: How do amiodarone and lidocaine work on the heart? Amiodarone Blocks potassium channels (Class III effect). Also blocks sodium and calcium channels. Additional noncompetitive beta-blocker effects. Stabilizes cardiac tissue, slows heart rate, and suppresses both atrial and ventricular arrhythmias. Lidocaine Blocks fast sodium channels in ventricular tissue (Class Ib). Shortens the action potential in ventricular myocardium, especially in ischemic tissue. Suppresses abnormal automaticity in damaged/irritable myocardium. Which one should you pick for a patient in vtach/vfib cardiac arrest? The current guidelines recommend amiodarone for shock-refractory cases but this is based on randomized trials showing better arrhythmia termination and short-term outcomes, but not long-term survival benefits. Two recent studies suggest that lidocaine might actually be preferable. A 2023 paper published in Chest Performed a large retrospective cohort study for treatin