What is the first drug used for a wide QRS complex tachycardia?

The appropriate first drug used for wide QRS complex tachycardia is amiodarone. This medication is an antiarrhythmic that works by prolonging the action potential and refractory period in cardiac tissues, which can help to stabilize the heart's rhythm during tachycardia. It is particularly useful in cases of ventricular tachycardia and certain atrial arrhythmias with a wide QRS complex.

Amiodarone is favored in emergency situations due to its broad spectrum of action and its ability to effectively manage various types of tachyarrhythmias. It is administered intravenously to provide rapid therapeutic effects.

In contrast, other options like adenosine are typically used for narrow-complex tachycardias and may not be effective for wide QRS scenarios. Propranolol, a beta-blocker, may also help with tachyarrhythmias but is not the first-line choice in this context due to its slower onset of action and the complexity of managing wide QRS tachycardias. Lidocaine is an antiarrhythmic but is generally utilized in specific settings, particularly in ventricular arrhythmias and is not the immediate choice for wide QRS tachycardias. Thus, amiodar