Journal of Applied Physiology, Vol 76, Issue 2 875-881, Copyright © 1994 by American Physiological Society
Effect of chronic thromboembolism on the pulmonary artery pressure-flow relationship in dogs
M. A. Olman, R. Z. Gan, R. T. Yen, I. Villespin, R. Maxwell, C. Pedersen, R. Konopka, J. Debes and K. M. Moser
Division of Pulmonary and Critical Care, University of California at San Diego, La Jolla 92103.
To understand the hemodynamic alterations associated with chronic
thromboembolic pulmonary hypertension, the large pulmonary arteries of
mongrel dogs were chronically obstructed with lysis-resistant thrombi.
Pulmonary hemodynamics were experimentally measured and described by
multipoint pulmonary arterial pressure (PAP) vs. flow plots. In nine
anesthetized chronically embolized dogs, but not in six control dogs, the
PAP-flow line shifted significantly upward in a parallel fashion by 4.2 +/-
0.7 mmHg. The postembolic pulmonary circulation was further characterized
by predictions from a morphometric-based elastic tube and sheet flow model
of the canine pulmonary circulation. After model validation with the
preembolic PAP-flow data, the derived postembolic PAP matched the in vivo
results to within 1 mmHg. A detailed analysis of the model-derived PAP drop
revealed that the PAP-flow line shift can be accounted for by a novel fixed
resistor in the largest obstructed pulmonary artery.
