Pulmonary arterial compliance at rest and exercise in normal humans
Slife, D.M.; Latham, R.D.; Sipkema, P.; Westerhof, N.
American Journal of Physiology 258(6 Pt 2): H1823-H1828
1990
ISSN/ISBN: 0002-9513 PMID: 2360672 Document Number: 349799
We evaluated the feasibility of determining pulmonary arterial compliance (Cp) by a parameter estimation procedure based on the three-element windkessel model. Eight normal patients studied with multisensor micromanometry technology had simultaneous rest and exercise pulmonary artery pressures (PAP) and flows recorded. These were submitted to the model and independent methods to determine Cp, pulmonary characteristic impedance (Zc), and pulmonary vascular resistance (PVR). Significant changes in heart rate, PAP, and stroke volume (P < 0.05) occurred with exercise. In comparing rest and exercise Zc and PVR values determined by the model and independent methods, and in comparing each method for these values, there was no significant difference. Model-derived and independently derived estimates of Cp were significantly different at rest (P < 0.04) and exercise (P < 0.001). There was no significant difference between rest and exercise values of Cp by either method. The model estimates of PVR at rest (64 .+-. 11 dyn .cntdot. s .cntdot. cm-5) and exercise (41 .+-. 7 dyn .cntdot. s .cntdot. cm-5) (P = 0.06) and the model Zc value at rest (22 .+-. 3 dyn .cntdot. s .cntdot. cm-5) were appropriate. The model Cp values at rest (0.22 .+-. 0.05 ml .cntdot. mm Hg-1 .cntdot. kg-1) correlated with previously reported normalized values in other species. This study reports the successful use of a parameter estimation procedure based on the three-element windkessel model to describe pulmonary artery compliance in normal humans.