ACLS Emergency Pharmacology 4

Question 1

For a stable narrow-complex tachycardia that does not respond to vagal maneuvers, what is the first drug of choice?

Accepted Answer

Adenosine 6 mg rapid IV push

Answer

Adenosine 6 mg rapid IV push is the first pharmacological treatment for stable regular narrow-complex SVT.

Question 2

Procainamide is preferred over amiodarone for stable wide-complex tachycardia in which clinical scenario?

Accepted Answer

Pre-excitation syndrome (WPW) with AF

Answer

Procainamide is preferred over amiodarone for WPW with AF because it does not slow AV nodal conduction preferentially.

Question 3

What is the primary mechanism of action of adenosine in terminating SVT?

Accepted Answer

Temporary AV nodal blockade interrupting reentry

Answer

Adenosine transiently blocks AV nodal conduction, interrupting the reentrant circuit responsible for most SVTs.

Question 4

A patient in third-degree AV block is awaiting transcutaneous pacing. Which drug can be used as a temporizing measure?

Accepted Answer

Atropine 0.5 mg IV

Answer

Atropine 0.5 mg IV can increase heart rate temporarily while preparing for transcutaneous pacing in symptomatic bradycardia.

Question 5

Dopamine infusion is used for post-resuscitation hypotension. At what dose range does it primarily act as a vasopressor?

Accepted Answer

10–20 mcg/kg/min

Answer

At 10–20 mcg/kg/min, dopamine primarily stimulates alpha-1 receptors causing vasoconstriction and increased blood pressure.

ACLS Practice Test