A 65-year-old man with a 40 pack-year smoking history and GOLD stage 4 COPD presents to the emergency department with acute dyspnea. His wife reports he has had progressive exercise intolerance over the past 6 months. Vital signs: HR 104/min, RR 26/min, BP 128/82 mmHg, SpO2 84% on room air. Physical examination reveals barrel chest, pursed-lip breathing, and prominent jugular venous distension. Chest X-ray shows hyperinflation and flattened diaphragms without focal infiltrates. Computed tomography pulmonary angiography (CTPA) is negative for pulmonary embolism. Transthoracic echocardiography demonstrates an estimated pulmonary artery systolic pressure of 62 mmHg with right ventricular dilation. Which of the following mechanisms most likely accounts for the pulmonary hypertension in this patient?
- A)Chronic hypoxic vasoconstriction and medial hypertrophy of pulmonary arterioles secondary to obstructive lung diseaseGABARITO
- B)Acute thromboembolism with incomplete thrombolytic response despite negative CTPA
- C)Mitral stenosis causing postcapillary pulmonary hypertension
- D)Left ventricular systolic dysfunction from myocardial infarction
- E)Acute respiratory distress syndrome with increased alveolar-capillary permeability
Explicação
Chronic COPD causes pulmonary hypertension through multiple mechanisms: chronic alveolar hypoxia triggers hypoxic pulmonary vasoconstriction, which leads to medial smooth muscle hypertrophy and intimal fibrosis of pulmonary arterioles. This progressive vascula... Ver explicação completa e trilha adaptativa →