At 4500 m altitude, chronic hypoxic pulmonary vasoconstriction leads to which of the following hemodynamic changes?

• A Decreased pulmonary artery pressure and decreased pulmonary vascular resistance
• B Increased pulmonary artery pressure and increased pulmonary vascular resistance ✓
• C Increased pulmonary artery pressure with unchanged pulmonary vascular resistance
• D Decreased pulmonary artery pressure and increased pulmonary vascular resistance

Explanation

Chronic hypoxia triggers hypoxic pulmonary vasoconstriction, causing smooth muscle hypertrophy in pulmonary arterioles. This raises both pulmonary artery pressure and pulmonary vascular resistance. Unlike systemic vessels, pulmonary vessels constrict in response to hypoxia. The decreased pressure option is opposite to the known pathophysiology of high-altitude pulmonary hypertension.

Reference: Ganong's Review of Medical Physiology, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.