In a patient with Graves disease and atrial fibrillation with rapid ventricular response, which agent is preferred for rate control?

• A. Diltiazem
• B. Lidocaine
• C. Adenosine
• D. Atenolol

Answer: (D)

Controlling the ventricular rate in atrial fibrillation with rapid ventricular response is especially important in Graves disease because the hyperadrenergic state drives a faster heart rate and worsens palpitations and perfusion. A beta-blocker does two things at once: it blocks sympathetic stimulation of the heart to slow AV nodal conduction, and it softens thyrotoxic symptoms. A cardioselective beta-blocker like atenolol reduces the ventricular rate effectively with a lower risk of bronchospasm compared with nonselective options.

Other choices aren’t ideal for rate control in this context. A non-dihydropyridine calcium channel blocker can slow the AV node, but beta-blockade is preferred in Graves due to its broader relief of hyperadrenergic symptoms and better tolerability in this scenario. Lidocaine is targeted at ventricular arrhythmias, not AF rate control. Adenosine terminates some SVTs by momentarily blocking AV nodal conduction but does not reliably control or terminate atrial fibrillation with RVR.

So, atenolol is the best choice because it effectively slows the AV node in the hyperthyroid state with good safety and symptom relief.