A 60-year-old male with a history of angina pectoris is prescribed a medication that decreases heart rate, contractility, and myocardial oxygen demand by blocking beta-adrenergic receptors. Which of the following is the primary mechanism of action of this drug class in treating his angina?

The correct answer to the question "A 60-year-old male with a history of angina pectoris is prescribed a medication that decreases heart rate, contractility, and myocardial oxygen demand by blocking beta-adrenergic receptors. Which of the following is the primary mechanism of action of this drug class in treating his angina?" is Option B: Reduces cardiac workload and oxygen consumption.

The other options — A) Increases coronary artery vasodilation, C) Inhibits platelet aggregation, D) Enhances myocardial contractility — are incorrect for this USMLE Exam Prep question. As explained above: Beta-blockers reduce heart rate, contractility, and blood pressure, thereby decreasing myocardial oxygen demand and cardiac workload. This mechanism is crucial for relieving angina symptoms caused by…