"form a broad network with pre- and postcapillary anastomoses to the pulmonary system"
"Historically, it was thought that pulmonary infarction was more common in older patients with comorbidities, especially coexisting cardiovascular disease and underlying malignancy, but rare in the young and otherwise healthy. However, research in 2015 questioned orthodox thinking with evidence that greater patient stature, decreased age (peak risk at age 40), and smoking of cigarettes are independent risk factors for developing pulmonary infarction 2,3. Furthermore, it was shown that heart failure, malignancy and pneumonia were not risk factors for the development of pulmonary infarction 2."
"Usually these parenchymal findings are transient; the blood cells extravasated into the alveolar and bronchial cavities are resorbed, and the tissue regenerates ref. However, the injury may progress to infarction in certain circumstances:"
"reduced flow in the bronchial arteries (e.g. shock, hypotension, use of vasodilators)"
"increased pulmonary venous pressure (e.g. elevated pulmonary venous pressure, interstitial oedema)"