title: Association between echocardiographic structural parameters and body weight in Wistar rats.
abstract: BACKGROUND
  The association between echocardiographic structural parameters and body weight (BW) during rat development has been poorly addressed. We evaluated echocardiographic variables: left ventricular (LV) end-diastolic (LVDD) and end-systolic (LVSD) diameters, LV diastolic posterior wall thickness (PWT), left atrial diameter (LA), and aortic diameter (AO) in function of BW during development.Results/Materials and Methods: Male Wistar rats (n = 328, BW: 302-702 g) were retrospectively used to construct regression models and 95% confidence intervals relating to cardiac structural parameters and BW. Adjusted indexes were significant to all relationships; the regression model for predicting LVDD (R2 = 0.678; p < 0.001) and AO (R2 = 0.567; p < 0.001) had the highest prediction coefficients and LA function the lowest prediction coefficient (R2 = 0.274; p < 0.01). These relationships underwent validation by performing echocardiograms on additional rats (n = 43, BW: 300-600 g) and testing whether results were within confidence intervals of our regressions. Prediction models for AO and LA correctly allocated 38 (88.4%) and 39 rats (90.7%), respectively, within the 95% confidence intervals. Regression models for LVDD, LVSD, and PWT included 27 (62.7%), 30 (69.8%), and 19 (44.2%) animals, respectively, within the 95% confidence intervals.
  
  
  CONCLUSIONS
  Increase in cardiac structures is associated with BW gain during rat growth. LA and AO can be correctly predicted using regression models; prediction of PWT and LV diameters is not accurate.
authors.affiliation: School of Physical Therapy, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil.
authors.forename: Silvio A
authors.initials: SA
authors.lastname: Oliveira-Junior
authors.affiliation: School of Physical Therapy, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil.
authors.forename: Paula F
authors.initials: PF
authors.lastname: Martinez
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: William Y C
authors.initials: WYC
authors.lastname: Fan
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Bruno T
authors.initials: BT
authors.lastname: Nakatani
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Luana U
authors.initials: LU
authors.lastname: Pagan
authors.affiliation: Botucatu Biosciences Institute, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Padovani
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Cicogna
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Marina P
authors.initials: MP
authors.lastname: Okoshi
authors.affiliation: Botucatu Medical School, Sao Paulo State University, UNESP, Botucatu, SP, Brazil.
authors.forename: Katashi
authors.initials: K
authors.lastname: Okoshi
mesh_terms: D000818:Animals; D001835:Body Weight; D004452:Echocardiography; D006321:Heart / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006325:Heart Atria; D006352:Heart Ventricles; D008297:Male; D017711:Nonlinear Dynamics; D051381:Rats; D017208:Rats, Wistar; D012189:Retrospective Studies
keywords: cardiac structures; development; echocardiogram; physiological cardiac remodeling; rat