A 74-year-old woman is brought to the emergency department due to chest pain. The patient reports that she went to bed feeling well and woke up in the middle of the night with severe, crushing chest pain that radiated to her left arm. She has had similar episodes over the past year that typically occur after a mild work and spontaneously resolve after several minutes. The patient has a history of occasional migraine that responds to acetaminophen. She does not use tobacco, alcohol, or illicit drugs. Blood pressure is 150/100 mm Hg, pulse is 110/min, and respirations are 14/min. On physical examination, the patient appears distressed and is diaphoretic. ECG reveals ST-segment elevations in leads I, aVL, and V4-V6. The patient is given nitroglycerin, which improves her symptoms. Coronary angiography reveals a ruptured atherosclerotic plaque, with a thrombus in the left circumflex artery that causes near-total occlusion. Which of the following substances was most likely secreted by these endothelial cells to help decrease thrombus propagation by inhibiting platelet aggregation?

Question

A 74-year-old woman is brought to the emergency department due to chest pain. The patient reports that she went to bed feeling well and woke up in the middle of the night with severe, crushing chest pain that radiated to her left arm. She has had similar episodes over the past year that typically occur after a mild work and spontaneously resolve after several minutes. The patient has a history of occasional migraine that responds to acetaminophen. She does not use tobacco, alcohol, or illicit drugs. Blood pressure is 150/100 mm Hg, pulse is 110/min, and respirations are 14/min. On physical examination, the patient appears distressed and is diaphoretic. ECG reveals ST-segment elevations in leads I, aVL, and V4-V6. The patient is given nitroglycerin, which improves her symptoms. Coronary angiography reveals a ruptured atherosclerotic plaque, with a thrombus in the left circumflex artery that causes near-total occlusion. Which of the following substances was most likely secreted by these endothelial cells to help decrease thrombus propagation by inhibiting platelet aggregation?

Quizplus · Accepted Answer

Eductional Objective: Prostacyclin (prostaglandin I2) is synthesized from prostaglandin H2 by prostacyclin synthase in vascular endothelial cells.  Once secreted, it inhibits platelet aggregation and causes vasodilation to oppose the functions of thromboxane A2 and help maintain vascular homeostasis.

A 74-Year-Old Woman Is Brought to the Emergency Department Due