Pathophysiology
Clinical meaning
Pulmonary infarction occurs when a pulmonary embolism completely obstructs an end-artery, cutting off both pulmonary arterial and bronchial collateral blood supply to a segment of lung tissue. The resulting ischemia causes coagulative necrosis of alveolar tissue, hemorrhagic infarction, and pleural inflammation. Only 10-15% of pulmonary emboli result in true infarction because the lung has dual blood supply (pulmonary and bronchial arteries). Infarction is more likely in patients with compromised bronchial circulation due to heart failure, COPD, or large embolic burden.