A 38-year-old woman comes to the physician because of a 4-month history of worsening fatigue. She has had occasional exertional chest pain and shortness of breath over the past year but has not seen a physician. She takes no medications. Her temperature is 37°C (98.6°F), pulse is 94/min, respirations are 24/min, and blood pressure is 130/84 mm Hg. Physical examination reveals a loud pulmonic component of S2 but is otherwise unremarkable. Chest x-ray is normal. Echocardiography shows elevated pulmonary artery systolic pressure and right ventricular hypertrophy. Left ventricular structure and function are normal. Which of the following patterns of chemical mediators is most likely present in this patient's pulmonary arteries?

Question

A 38-year-old woman comes to the physician because of a 4-month history of worsening fatigue. She has had occasional exertional chest pain and shortness of breath over the past year but has not seen a physician. She takes no medications. Her temperature is 37°C (98.6°F), pulse is 94/min, respirations are 24/min, and blood pressure is 130/84 mm Hg. Physical examination reveals a loud pulmonic component of S2 but is otherwise unremarkable.  Chest x-ray is normal.  Echocardiography shows elevated pulmonary artery systolic pressure and right ventricular hypertrophy.  Left ventricular structure and function are normal.  Which of the following patterns of chemical mediators is most likely present in this patient's pulmonary arteries?

Quizplus · Accepted Answer

Eductional Objective: Pulmonary arterial hypertension results from endothelial dysfunction that leads to an increase in vasoconstrictive, proproliferative mediators (eg, endothelin, thromboxane A2) and a decrease in vasodilative, antiproliferative mediators (eg, nitric oxide, prostacyclin).  The relative imbalance in these mediators leads to vasoconstriction and intimal-wall thickening with a consequent increase in pulmonary vascular resistance.

A 38-Year-Old Woman Comes to the Physician Because of a 4-Month