Which medication is a beta-blocker commonly used to treat tachyarrhythmias?

Which medication is a beta-blocker commonly used to treat tachyarrhythmias?

• A. Adenosine
• B. Metoprolol
• C. Dopamine
• D. Norepinephrine

Answer: (B)

Beta-blockers slow the heart rate by blocking sympathetic stimulation to the heart, especially reducing AV nodal conduction to lower the ventricular rate during tachyarrhythmias. Metoprolol is a cardioselective beta-1 blocker, so it primarily affects the heart, decreasing automaticity and AV conduction. This makes it a common choice for rate control in tachyarrhythmias such as atrial fibrillation with rapid ventricular response or SVT. Adenosine, while useful for terminating certain SVTs by briefly blocking the AV node, is not a chronic rate-control beta-blocker. Dopamine and norepinephrine are vasopressors/inotropes used to support blood pressure and cardiac output and can increase heart rate, not primarily to treat tachyarrhythmias.

Beta-blockers slow the heart rate by blocking sympathetic stimulation to the heart, especially reducing AV nodal conduction to lower the ventricular rate during tachyarrhythmias. Metoprolol is a cardioselective beta-1 blocker, so it primarily affects the heart, decreasing automaticity and AV conduction. This makes it a common choice for rate control in tachyarrhythmias such as atrial fibrillation with rapid ventricular response or SVT.

Adenosine, while useful for terminating certain SVTs by briefly blocking the AV node, is not a chronic rate-control beta-blocker. Dopamine and norepinephrine are vasopressors/inotropes used to support blood pressure and cardiac output and can increase heart rate, not primarily to treat tachyarrhythmias.