**Question:** A sixteen-year-old girl is found to have paroxysmal attacks of rapid heart rate. The antiarrhythmic of choice in most cases of acute AV nodal tachycardia is:

A. Verapamil
B. Amiodarone
C. Flecainide
D. Sotalol

**Correct Answer:** **D. Sotalol**

**Core Concept:** Acute AV nodal tachycardia is a type of supraventricular tachycardia (SVT) characterized by rapid heart rate caused by abnormal impulse conduction through the AV node. The choice of antiarrhythmic depends on the underlying mechanism of the tachycardia.

**Why the Correct Answer is Right:** Sotalol is a beta-blocker and class III antiarrhythmic agent that blocks beta-receptors in the atria and ventricles, reducing automaticity and conduction in the AV node. In acute AV nodal tachycardia, Sotalol's dual action on both beta-receptors and AV node makes it a suitable choice for controlling tachycardia.

**Why Each Wrong Option is Incorrect:**

A. Verapamil is a calcium channel blocker which primarily affects the sinoatrial (SA) node, reducing automaticity and conduction. It is not as effective in acute AV nodal tachycardia as sotalol.

B. Amiodarone is a broad-spectrum antiarrhythmic agent targeting various cardiac ion channels. While it can be effective in some cases, its action on the AV node is not as specific as sotalol, making it less ideal for acute AV nodal tachycardia.

C. Flecainide is a class Ic antiarrhythmic agent targeting sodium channels, predominantly used in atrial fibrillation and flutter. Its mode of action does not address the specific issue in AV nodal tachycardia.

**Clinical Pearl:** In cases of acute AV nodal tachycardia, choosing the appropriate antiarrhythmic agent is crucial for effective treatment. Sotalol stands out due to its dual action on beta-receptors and AV node, making it the preferred choice in this scenario.