A 72-year-old man is brought to the emergency department after experiencing waxing and waning chest pressure for several hours. When the patient walks briskly up the stairs, he says he gets a similar sensation that lasts 5-10 minutes. He has a significant medical history for hypertension and hyperlipidemia; he has been noncompliant with prescribed medical therapy and follow-up visits. The patient has a smoking history of 25 packs per year. The blood pressure is 211/105 mm Hg, and the pulse rate is 88 beats per minute. A chest examination reveals no heart murmurs and clear lungs. The ECG demonstrates sinus rhythm and nonspecific ST-segment changes. When a medication is administered intravenously, the following hemodynamic effects are observed in comparison to baseline: Which of the following medications was most likely used in this patient?

Question

A 72-year-old man is brought to the emergency department after experiencing waxing and waning chest pressure for several hours. When the patient walks briskly up the stairs, he says he gets a similar sensation that lasts 5-10 minutes. He has a significant medical history for hypertension and hyperlipidemia; he has been noncompliant with prescribed medical therapy and follow-up visits. The patient has a smoking history of 25 packs per year. The blood pressure is 211/105 mm Hg, and the pulse rate is 88 beats per minute. A chest examination reveals no heart murmurs and clear lungs. The ECG demonstrates sinus rhythm and nonspecific ST-segment changes. When a medication is administered intravenously, the following hemodynamic effects are observed in comparison to baseline:  Which of the following medications was most likely used in this patient?

Quizplus · Accepted Answer

Eductional Objective: Labetalol is a nonselective vasodilatory beta blocker that blocks beta-1, beta-2, and alpha-1 adrenergic receptors.  Alpha-1 receptor blockade outweighs beta-2 receptor blockade to cause peripheral vasodilation with decreased venous return and lower systemic vascular resistance.  The relatively balanced vasodilation reduces blood pressure without changing stroke volume.  Beta-1 receptor blockade overrides the expected baroreflex-mediated increase in heart rate, resulting in overall decreased heart rate.

A 72-Year-Old Man Is Brought to the Emergency Department After