Noninvasive estimation of pulmonary arterial pressure by analysis of pulmonary blood-flow distribution.
To determine whether a correlation exists between pulmonary arterial (PA) pressure (Pa) and the distribution of pulmonary blood flow, this distribution was measured in four upright dogs in the control state and during intravenous infusions of epinephrine or prostaglandin F2 alpha. During suspension of respiration, 15 mCi of Xe-133 were injected intravenously, and perfusion and equilibration lung images were recorded with a scintillation camera. The procedure was performed several times on each dog, with and without pharmacological elevation of PA pressure by 5 to 50 cm H2O. For each scintigram, the relative blood flow per unit ventilated lung volume (F) was plotted against centimeters above the hilum (h). Pulmonary arterial pressure was derived from each curve, assuming the relation F = B(Pa - hD)2, where B = constant and D = specific gravity of blood. Calculated PA pressure correlated strongly (r = 0.83) with measured PA pressure, suggesting a possible means of noninvasive estimation of PA pressure.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D004837:Epinephrine / Q000494:pharmacology; D008168:Lung / Q000000981:diagnostic imaging; D011460:Prostaglandins F / Q000494:pharmacology; D011651:Pulmonary Artery; D011652:Pulmonary Circulation; D011877:Radionuclide Imaging
D011460:Prostaglandins F; D004837:Epinephrine