A 59-year-old woman presented with an abrupt onset of palpitations accompanied by a vague complaint of feeling ill. Subsequent Holter monitoring revealed atrial fibrillation with a ventricular response up to 152 bpm. The patient's past history included primary hyperparathyroidism and intermittent claudication for 3 years, apparently due to peripheral occlusive arteriosclerosis. Which of the following drugs would be appropriate for the chronic control of the patient's arrhythmia?

Correct Answer: B

Rationale: The correct answer is B: Propranolol. Propranolol is a beta-blocker that can be used for rate control in atrial fibrillation. It works by blocking the effects of adrenaline on the heart, slowing the heart rate and reducing the force of contraction. In this case, the patient has atrial fibrillation with a rapid ventricular response, and propranolol can help slow the heart rate to a more appropriate level. A: Digoxin is primarily used for rate control in patients with heart failure, not as the first-line agent for atrial fibrillation with a rapid ventricular response. C: Verapamil is a calcium channel blocker that can also be used for rate control in atrial fibrillation, but beta-blockers are generally preferred in patients with concomitant peripheral artery disease. D: Lidocaine is a local anesthetic and antiarrhythmic agent used for ventricular arrhythmias, not appropriate for atrial fibrillation.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.