Assessment of ventricular relaxation in the developing chick embryo using a monoexponential model. Am J Physiol 1994 Aug;267(2 Pt 2):H631-5
Date
08/11/1994Pubmed ID
8067418DOI
10.1152/ajpheart.1994.267.2.H631Scopus ID
2-s2.0-0028093094 (requires institutional sign-in at Scopus site) 9 CitationsAbstract
In this study, the ventricular pressure decline during isovolumic relaxation in early diastole was modeled by regressing pressure and pressure change vs. time to a monoexponential formula: P(t) = P infinity+P0e-t/tau, where P(t) is ventricular pressure at time t, P infinity is the pressure in the fully relaxed ventricle, P0 is the pressure at the end of ventricular ejection, and tau is the ventricular relaxation rate constant. Analysis was performed on 330 ventricular pressure waveforms from 22 chick embryos, stages 17, 23, and 26, during baseline and following cardiac cycle length perturbation. Three computational models were evaluated. Based on analysis of the confidence intervals of estimates of P infinity and analysis of residuals, a least-squares nonlinear regression of pressure vs. time, which allowed estimates of tau and P infinity, best approximated the pressure decline. Isovolumic pressure decline in the embryonic heart is well approximated by a monoexponential model if both P infinity and tau are estimated. Negative values of P infinity during early stages of cardiac morphogenesis support the idea that diastolic suction plays a role in ventricular filling in the developing heart.
Author List
Braunstein JB, Donovan M, Hughes S, Benson DW JrMESH terms used to index this publication - Major topics in bold
AnimalsChick Embryo
Embryonic and Fetal Development
Heart
Models, Cardiovascular
Pressure
Ventricular Function
