Which pharmacologic class is commonly used to prophylactically reduce postoperative atrial fibrillation after CABG?

• A. Beta-blockers.
• B. No prophylaxis is used.
• C. Only calcium channel blockers.
• D. Amiodarone without beta-blockers.

Answer: (A)

Reducing sympathetic stimulation to the heart during the perioperative period is the key strategy to prevent atrial fibrillation after CABG. Beta-blockers achieve this by blocking beta-adrenergic receptors, which lowers heart rate, reduces atrial ectopy, and stabilizes the atrial myocardium when the heart is especially susceptible after surgery. This combination consistently lowers the incidence of postoperative AF and is standard perioperative therapy in most guidelines, usually started before surgery and continued for several days to weeks after.

Calcium channel blockers can be used for rate control in selected patients or when beta-blockers are not suitable, but they don’t have as strong or consistent evidence for AF prophylaxis as beta-blockers. Amiodarone is also effective, particularly in high-risk patients or when beta-blockers can’t be used, and it may be used as an alternative or adjunct, but the default first-line prophylaxis is beta-blockers.