P. Segers et al., Pulmonary arterial compliance in dogs and pigs: the three-element windkessel model revisited, AM J P-HEAR, 46(2), 1999, pp. H725-H731
Citations number
21
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
In six dogs and six weight-matched miniature pigs at baseline and after pul
monary embolization, pulmonary arterial compliance was determined using the
pulse pressure method (C-PPM), the three-element windkessel model (CWK-3),
and the ratio of stroke volume to pulse pressure (SV/PP). C-PPM was lower
in pigs than in dogs at baseline (0.72 +/- 0.23 vs. 1.14 +/- 0.29 ml/mmHg,
P < 0.05) and after embolism (0.37 +/- 0.14 vs. 0.54 +/- 0.16 ml/mmHg, P =
0.07) at; matched flow, but not at matched flow and pressure. C-PPM showed
the expected inverse relation with pressure and a direct relation with flow
. CWK-3 was closely correlated with C-PPM, except for all dogs at baseline
where CWK-3 was up to 100% higher than C-PPM. Excluding these data, regress
ion analysis yielded CWK-3 = -0.01 +/- 1.30.C-PPM (r(2) = 0.97). CWK-3 was
found to be unreliable when input impedance first harmonic modulus was clos
e to characteristic impedance, i.e., when reflections were small. SV/PP cor
related well with C-PPM (SV/PP = -0.10 + 1.76.C-PPM, r(2) = 0.89). We concl
ude that 1) C-PPM is a consistent estimate of pulmonary arterial compliance
in pigs and dogs, 2) CWK-3 and SV/PP overestimate compliance, and 3) CWK-3
is unreliable when wave reflections are small.