title: Pulmonary vascular abnormalities and ventilation-perfusion relationships in mild chronic obstructive pulmonary disease.
abstract: Morphologic changes in pulmonary muscular arteries may modify the mechanisms that regulate the pulmonary vascular tone and contribute to maintaining an adequate ventilation-perfusion (VA/Q) matching in patients with chronic obstructive pulmonary disease (COPD). To analyze the relationships between the abnormalities of pulmonary muscular arteries and the degree of VA/Q inequality, and to assess the effect of these abnormalities on the changes in VA/Q relationships induced by oxygen breathing, we studied a group of patients with mild COPD undergoing resective lung surgery. According to the degree of airflow obstruction and the increase in VA/Q mismatch produced by 100% O2 breathing (delta logSD Q), patients were divided into three groups: (A) patients with normal lung function, (B) patients with airflow obstruction and a high response to oxygen (delta logSD Q > 0.4), and (C) patients with airflow obstruction and a low response to oxygen (delta logSD Q < 0.4). Pulmonary arteries in Groups B and C showed narrower lumens and thicker walls than in Group A. These morphologic changes were produced mainly by an enlargement of the intimal layer and were more pronounced in Group C than in Group B. The assessment of intimal area as a function of artery diameter showed that the increase in intima in Group C took place predominantly in arteries with small diameters (< 500 microns). The mean intimal area on each subject correlated with both the PaO2 value (r = -0.46, p < 0.05) and the overall index of VA/Q mismatching (r = 0.51, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine (Servei de Pneumologia), Hospital Clínic, Barcelona, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Barberà
authors.forename: A
authors.initials: A
authors.lastname: Riverola
authors.forename: J
authors.initials: J
authors.lastname: Roca
authors.forename: J
authors.initials: J
authors.lastname: Ramirez
authors.forename: P D
authors.initials: PD
authors.lastname: Wagner
authors.forename: D
authors.initials: D
authors.lastname: Ros
authors.forename: B R
authors.initials: BR
authors.lastname: Wiggs
authors.forename: R
authors.initials: R
authors.lastname: Rodriguez-Roisin
mesh_terms: D005260:Female; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000473:pathology*; D011652:Pulmonary Circulation / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D017539:Tunica Intima / Q000473:pathology*; D014692:Ventilation-Perfusion Ratio / Q000502:physiology