Which statement about rate control in atrial fibrillation with preserved LV function is correct?

• A. Beta-blockers and non-dihydropyridine calcium channel blockers are first-line for rate control.
• B. ACE inhibitors are first-line for rate control.
• C. Nitrates are preferred for rate control.
• D. Digoxin alone is sufficient for all patients

Answer: (A)

Rate control in atrial fibrillation aims to slow the ventricular response by reducing AV nodal conduction, which improves symptoms and prevents tachycardia-induced issues. When the left ventricle is functioning normally, the best options to achieve reliable rate control are agents that directly slow AV nodal conduction: beta-blockers and non-dihydropyridine calcium channel blockers. These drugs blunt the effects of sympathetic stimulation and calcium entry in nodal tissue, lowering the heart rate both at rest and during exercise, which is especially desirable in maintaining a controlled rhythm without compromising overall cardiac function.

ACE inhibitors and nitrates don’t affect AV nodal conduction, so they don’t serve as rate-control therapies. Digoxin, while sometimes useful, has a slower onset and is often less effective during activity or with higher sympathetic tone; relying on it alone for rate control in patients with preserved LV function is not ideal.