CRAT Antiarrhythmic Medications and Clinical Interventions 1 — Questions and Answers
Question 1: Which antiarrhythmic drug is classified as a Class III agent and is commonly used for atrial fibrillation and ventricular tachycardia?
- Lidocaine
- Metoprolol
- Amiodarone (Correct answer)
- Adenosine
Correct answer: Amiodarone
Amiodarone is a Class III antiarrhythmic that blocks potassium channels to prolong repolarization and is widely used for both atrial and ventricular arrhythmias.
Question 2: Adenosine is the drug of choice for terminating which arrhythmia?
- Atrial fibrillation
- Ventricular fibrillation
- Paroxysmal supraventricular tachycardia (PSVT) (Correct answer)
- Torsades de Pointes
Correct answer: Paroxysmal supraventricular tachycardia (PSVT)
Adenosine transiently blocks AV node conduction and is the first-line drug for terminating PSVT by interrupting re-entry circuits involving the AV node.
Question 3: Which medication should be avoided in patients with Wolff-Parkinson-White (WPW) syndrome presenting with atrial fibrillation?
- Amiodarone
- AV nodal blocking agents (e.g., adenosine, verapamil) (Correct answer)
- Procainamide
- Magnesium sulfate
Correct answer: AV nodal blocking agents (e.g., adenosine, verapamil)
AV nodal blocking agents are contraindicated in WPW with AF because they can enhance conduction through the accessory pathway, potentially causing ventricular fibrillation.
Question 4: Magnesium sulfate is the treatment of choice for:
- First-degree AV block
- Torsades de Pointes (Correct answer)
- Sinus bradycardia
- Junctional escape rhythm
Correct answer: Torsades de Pointes
IV magnesium sulfate is the first-line treatment for Torsades de Pointes because it stabilizes the cardiac membrane and shortens the QT interval.
Question 5: Atropine is administered in cardiac emergencies primarily to treat:
- Ventricular tachycardia
- Symptomatic bradycardia (Correct answer)
- Atrial flutter
- Premature ventricular contractions
Correct answer: Symptomatic bradycardia
Atropine blocks vagal (parasympathetic) tone to increase heart rate and is the first-line drug for symptomatic bradycardia per ACLS guidelines.
Question 6: Which Class I antiarrhythmic is commonly used for ventricular arrhythmias, especially in the acute setting of myocardial infarction?
- Verapamil
- Lidocaine (Correct answer)
- Digoxin
- Diltiazem
Correct answer: Lidocaine
Lidocaine is a Class IB sodium channel blocker used for ventricular arrhythmias, particularly in the context of acute myocardial infarction.
CRAT Antiarrhythmic Medications and Clinical Interventions 1
Which antiarrhythmic drug is classified as a Class III agent and is commonly used for atrial fibrillation and ventricular tachycardia?