A 68-year-old male presents to the ED with palpitations and dizziness. ECG shows atrial fibrillation with a rapid ventricular rate of 140 bpm. His blood pressure is 110/70 mmHg, and he denies chest pain or shortness of breath. Which of the following is the most appropriate initial management step?

The correct answer to the question "A 68-year-old male presents to the ED with palpitations and dizziness. ECG shows atrial fibrillation with a rapid ventricular rate of 140 bpm. His blood pressure is 110/70 mmHg, and he denies chest pain or shortness of breath. Which of the following is the most appropriate initial management step?" is Option B: Intravenous diltiazem.

The other options — A) Immediate direct current cardioversion, C) Oral amiodarone, D) Intravenous adenosine — are incorrect for this USMLE Exam Prep question. As explained above: For hemodynamically stable atrial fibrillation with rapid ventricular response, rate control is the initial goal. Intravenous calcium channel blockers (e.g., diltiazem) or beta-blockers are preferred…