Relation of geometry to certain aspects of hydrodynamics in larger pulmonary arteries

¹ Section of Clinical Biophysics, Cardiology Branch, National Heart Institute, National Institutes of Health, Bethesda, Maryland

Pressure-flow relationships in the major pulmonary artery of the dog associated with accelerations imposed on flow by the geometry of vessel walls were evaluated. Assuming irrotational flow, the pressure-flow relationships may be evaluated by numerical substitution of fluid boundary measurements into Bernoulli's equation. Fluid boundary dimensions were obtained from Jeltrate casts of the pulmonary arterial tree in eight dogs. The results indicate that significant pressure differences may occur in the pulmonary artery at peak systolic blood flows due to nonuniformity and curvature of these vessels.